Suppose that Khufu, pharaoh of Egypt and builder of the Great Pyramid of Giza, was introduced to the idea of an amusement park.

More specifically, suppose that he was visited by a time traveler and was invited to go on vacation with said traveler to the 21st century. On this vacation to a modern amusement park, he became so enthralled with roller coasters that, on returning to his time (which is at the point before construction on the Great Pyramid has begun, but after the foundation has been created), he decides to pour all his resources into building a roller coaster instead of a giant tomb. After all, roller coasters are fun, and it may well become a Wonder of the World for generations to enjoy, making his legacy unique compared to all other pharaohs. And besides, he can still build a nice portal to the afterlife in the form of a smaller, more economical pyramid, later.

And so, the prime question:

What is the biggest, most complex, most enjoyable ride that Khufu can construct within 20 years, using the same Egyptian-level technology and manpower that would have otherwise been used for building the Great Pyramid? Assume the structure is located on the Great Pyramid's foundation. Provide dimensions, and give explanations for technical elements such as loops or vertical drops, etc.

Bonus Questions:

  1. What is the most practical way of powering the roller coaster? Are there solutions besides slave powered ascent ramps?
  2. What is the maximum passenger service rate? (Number of individuals per train, number of concurrent trains running at a time, etc.)
  3. How safe is it? (Fatalities/Injuries per coaster run)
  4. How long can it remain functional? (Provided 60 years of active service to the end of the Old Kingdom in ~2490 BC, then total neglect there after. Can the structure and cars/trains be restarted with minimal repairs up to a certain point in time? We want this to be a Wonder of the Ancient World, is this possible?)
  5. How would history be affected? Specifically, would the Scientific and Industrial Revolutions have happened earlier and elsewhere had the Egyptians been exposed to the physics of movement via roller coaster mastery?

Some supplement material:

The Great Pyramid took between 10 and 20 years to build with between 15000 and 40000 workers. It weights 5.9 million tonnes, and its dimensions are accurate to tens of millimeters in terms of alignment and average deviation from flat.


January 2017 Updates:

Here is a slight addition to improve on the original prompt:

Khufu knows full well that the marvelous steel wheel, rails and bearings he got to see and experience on his trip are not a viable technology for his time. What he really wants to do is to try to replicate the experience as nearly as he can, namely:

  1. Fantastic, fast traversal of some kind of track which is open to the public (for a fee). This may devolve to it being a glorified bobsled track, but the closer to the modern experience, the better.
  2. Has tiered lines like modern amusement parks: The Standard Line is for commoners and tourists who have paid the park entrance fee. The Fast Line, for those who pay more or submit to a schedule. The Royal Line, reserved for the Pharaoh and his friends only.
  3. Designed to operate for centuries. As specified above, it will fall into a period of disuse for a time about 60 years after its completion, but say around 1000 BC, the park is started back up again. How well does it weather over ~1500 years of neglect? The Wonders of the Ancient World were sites that ancient tourists visited with good reason, and this site needs to be included in that same list in this alternate timeline.
  • $\begingroup$ The Great Sphere, everyone tries to climb up to the top while this colossal structure rolls about the winner(s) gets to see overall view of Egypt flooded with seas of blood while the moment last! $\endgroup$ – user6760 Jul 20 '15 at 23:31
  • $\begingroup$ "...he can still build a nice portal to the afterlife..." Or make them one and the same. Khufu founds the new cult of Ra-Lokhostr, in which prosperity in the afterlife is secured not by a wealthy burial, but by going out with as much westward velocity as possible. (Bonus: "How safe is it? (Fatalities/Injuries per coaster run)" With a 100% fatality rate, it's reliably unsafe.) $\endgroup$ – Tim Pederick Jul 21 '15 at 11:26
  • $\begingroup$ It's worth pointing out that Khufu's introduction of the modern wheel necessary to support the roller coaster would be an extremely significant contribution in and of itself. If the rollercoaster is going to be raised with wood like early rollercoasters, the introduction of nails and the metallurgy required to make them would also be a very big deal. Those byproducts of this effort alone would have allowed Egypt to extend its empire significantly... or they could build a shoddy rollercoaster... $\endgroup$ – GrinningX Jan 10 '17 at 20:19
  • $\begingroup$ As an offshoot of the above comment, for the sake of the question is it assumed that Khufu brought back the necessary ideas (and, ideally, specific knowledge about pre-requisite technologies) that are involved in rollercoasters? Keep in mind, as much as they would have been extremely helpful his pyramid was made without pullys/the wheel/nails/etc. Stuff that would be very helpful in building a rollercoaster. At the very least, without pullys bringing the cart back to the top of the launch area is going to be quite a nuisance and would significantly limit the number of rides per day. $\endgroup$ – GrinningX Jan 10 '17 at 20:25
  • $\begingroup$ Glad to see this question getting some new attention. I suppose I'll provide an additional piece of direction that I didn't specify when it was first opened: Khufu knows full well that the marvelous steel wheel, rails and bearings he got to see and experience on his trip are not a viable technology for his time. What he really want to do is to try to replicate the experience as nearly as he can, namely: Fantastic, fast traversal of some kind of track which is open to the public (for a fee), and is also available for him to use with his private "Royal" entrance which skips the line. $\endgroup$ – Steve Jan 10 '17 at 21:32

Aside from the other issues noted, the stone foundation of the roller coaster would provide a very jarring ride for the patrons. Wooden and metal roller coasters have some ability to "flex", which reduces some of the forces transmitted to the riders. A solid stone foundation will not.

All is not entirely lost, however. A stone foundation of an ancient roller coaster would require a much better cart, and Egyptian war chariots could provide the model for a roller coaster cart in this setting. Rather than the small wheels we associate with roller coasters, the war chariot has very large wheels, made of relatively lightweight and flexible wood. The axle and the body are also light and flexible to absorb the jolts that would be expected from a high speed chariot charge across the battlefield (trying to shoot an arrow or cast a spear from a wildly jolting rigid chariot would be extremely difficult. The driver and warrior would risk being tossed from the chariot as a minimum, and the warrior would not be able to aim with any sort of accuracy).

Of course, lightly built "sprung" chariots would not only be expensive, but also would not last very long due to the stresses imposed upon them. (Real chariots seem to have been disassembled and stored when not in use, and it is possible that they would be taken by wagon train closer to the battlefield, much like tanks today are carried on tank transporters for long moves). Unless the Pharaoh can charge a premium price for the ride (and perhaps the Kings of Assyria, Nubia, Mycenae and the Minoan kingdom would become fans), the expense of building and refurbishing roller coaster carts will probably bring the project to an end. Less fun loving successors will probably not bother to keep the ride running, since cart builders and slaves can be put to more productive use.

In later years, the remains of the roller coaster would be looked on as somewhat mysterious, since there would not be much memory or record of what it was used for (no crowds of peasants would be waiting at the gates to ride a Pharaonic roller coaster, it wold be reserved for royalty or the high priests), and of course there would be no carts to help decipher the mystery, unless one was disassembled and parked in a royal tomb.


The resources are all there to create a great roller-coaster.


This can be variable, but let's go with the largest we see today under construction for a wooden roller coaster, and allow for a 180' drop, and speeds of 72mph.


Khufu may have as many loops, such as this, that his heart desires. Keep in mind for your story that there may have to be more assisted ascents for the longer and faster his coaster may go.


Fortunately, a dryer climate is better for wood, but with wooden (not metal) pegs holding everything together, his engineers would do well to keep a close eye on the joints. Some support beams can be assisted by stone where there is little impact on the rider.

'Cars' will be tricky, as well, as they will be made of wood, with wooden wheels and joints. Seats can be leather stuffed with wool or any other soft material to reduce discomfort for the rider.


While you might have to rely on human or camel labor to draw the car upwards, a system of pulleys can reduce the effort on behalf of your 'engines'. The pull on the car will have to be rope-and-hook, but could certainly be doable.

The breaking mechanism will be tricky. Maybe one thick board (not your whole car) can stick below the car and catch a long trough of water, which will slow the cars; else, you can use rolling friction and a small hill to slow them down.


  1. Camels and a pully-system.
  2. This is highly variable, but I would anticipate 5 to 10 in single-file line; with the cars, I am confident from my experience in the Gulf that a single camel can pull this.
  3. Does Khufu really care about safety? Otherwise, you can ensure wheels run in a closed wooden track, and that inspections of the whole system are undertaken frequently by his talented engineers.
  4. 60 years of active service is possible with frequent maintenance. After that, there will be little left of your coaster within just a few years. Leather bands on the wheels, some bits might be preserved under sand, but that's it. Maybe there was a roller coaster back then...
  5. I can't imagine a roller coaster that lasted 60 years (and disintegrated after that) would affect modern history. Keep in mind that Egyptians had technological sophistication that was independently re-invented later in Europe, such as scientific empiricism (Ebers Papyrus, 1550BC), which was later attributed to philosophers such as John Locke in the 1800s.

Khufu's Space Mountain

Due to not having the technology to build metal rails or the time/resources to research them, the best option would be to cut the roller coaster path inside the pyramid, similar to the existing tomb paths. This way a cart with wheels on the top and bottom could be used to roll down a tube cut into the pyramid.

It is rather unlikely that a loop-the-loop could be achieved with the high-friction, unpowered carts available to Khufu at the time. The total vertical drop would be the entire height of the pyramid; 455' (139 m). The carts, powered by gravity, would be capable of making fairly hard curving-turns and could seat up to four Egyptian thrill seekers. Once reaching the bottom, the carts would need to be brought back to the top, most likely by slave labor. The uninitiated Egyptians would most likely be injured by not holding onto the cart well enough, they would have had no experience with such shifting apparent gravity. The carts would be the first to break down, likely not lasting even a year without significant maintenance. The track itself could remain for centuries. Massive changes to any industrial revolutions are unlikely, the original construction was a significant feat and it doesn't appear to have been duplicated.


@Samuel is on the right track (ahem), but got derailed (heh) by the idea of wheels.

You don't need wheels, when you have gravity.

Ancient Egyptian Amusement Park

Ignore some of the information on the wikipedia page.

You can use metal runners. Yes, you're going to wear out the runners. Yes, you're going to have to hand-smooth all of that, and the runners are going to cut grooves into your stone trough over time.

The principle of the sled is that you've got a lever which raises you and your seat up - which rests on woodblocks - so only the runners are exposed on the bottom. When you lower yourself, the blocks start friction braking, since the weight is no longer only on the runners. Bronze will probably last a while. Steel, of course, would be better. You might get some nice steel from India, and/or from meteorites.

But, 30-60mph! Almost as much fun as riding fumes (but far less dangerous)!

enter image description here

Given the right conditions, you can even operate injury-free. But that relies on the users not Darwin-ing themselves. The thrill-junkies will be a problem.

Everyone hikes their way to the top (no chairlifts for the plebes), so only the kings need to be hauled to the top; probably via slave-chair. They probably also get their own lane (no waiting).

Depending on the availability of runners, it's either for everyone (who can get into the Valley of the Kings, as that was a protected enclave until the 19th century), or for royalty only.

Best bet would be to pick some other cliffs along the Nile, and create the Khufu Memorial Park. You could even end in a splash-pool in the Nile (guard against crocs). Or make a bigger dam and run water-tubes, with actual running water in them.



Sorry, a coaster could not be made in 2570 BCE, at least not safely. There is one critical piece that cannot be recreated, the wheel bearings. All modern designs share the feature of top wheels, bottom wheels, and side wheels. Without all 3 sets of wheels, the coaster can leave the track. The bearings needed for these wheels are simply not possible without modern metals and the best metal available in 2570 BCE was bronze. Bronze is good enough for the rails, wood could be imported, but steel (or even iron) was not an option. The earliest coasters were built without the bottom wheels, and solved the flying off problem by enclosing side wheels in a channel. This does not help with the bearing failure problem though.

You cannot substitute a sleeve bearing made of bronze either as that requires high pressure lubricating oil -- the axle must ride on a sheet of pressured oil or you destroy the bearing very quickly.

I would suggest that Khufu could settle for a log fume ride, it would still have been a wonder of the world. An ice flume would not be possible given Egypt's climate, but the climate worked well for the Russian Ice Mountains that were the progenitor of the wheeled coaster.


While the Egyptians had the wheel, they did not have springs or durable metal. So a fast travelling cart would likely jump out of the track, or break the wooden wheels and become a serious accident.

Apparently, in real history the "ride" was boat trips on the Nile. It was cooler, for one thing. The rich had drink service and could watch the shores go by, the adventurous hunted crocs.


Something like this one might be possible, even made entirely out of stone https://en.wikipedia.org/wiki/La_Vibora This coaster has more of a halfpipe than a track, a lot like a bobsled course. It has low, wheeled cars. Lot's of fun. The keys to this would be as follows:

Show the good Pharaoh the ball bearing for the wheels. The wheels themselves could be lots of layers of leather over wood with bronze ball bearings and Bronze axles. Grease with animal fat. Wouldn't last all that long, but with the entire old Kingdom at your disposal, spares could be made in very large quantities. The cart itself is a very straightforward design. Tack wheels on the sides of a canoe and you are 90% of the way there. Just add some extra weight in a way to lower the center of gravity. All concepts Egyptian Engineers could grasp. When a cart starts to break down, just replace. The stone structure would remain for the ages.

A powered track to take riders to the top could be easily powered by an Ox driven treadmill. Carefully align everything to dimensions of Astrological significance and in 20 years, the God-King can go for a ride.


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