I'd like my earth-like world to have a naturally formed narrow strip of land that bridges a major sea. Now, before anyone rushes off to comment about island chains and land bridges, I'll add that I'm looking for unusually long, thin, and well, road-like formation.
Here are the guidelines:
The thinner the better. The ideal would be to form something like an actual road, approx 5-15 meters wide. Recognizing that this seems very, very unlikely, I'd still be happy with answers that helped me form a landmass as thin as a few kilometers.
The road should be shaped like a curved line. Thankfully, nature makes this is a lot easier than a straight one.
The road should span between 500-2500 km. I'm still working out the distances of my world, but this is a probable length for the sea in question. Being able to scale an idea up or down a bit would be a very good thing.
The road can be irregular. It can widen and narrow, rise and fall, so long as it retains a basically long and thin road-like shape.
The road does not have to be unbroken. The easier it is to walk the better, but small gaps are fine, so long as they can be crossed by bridges or ferries. I'd like there to be no more than a few large gaps, and none larger than approx 30 km. (Taking a cue from the English Channel.) That said, if a motivated ancient empire with good engineers and durable concrete could make it work in the long-term, then it's good.
The material can't be too unstable. It needs to last, and it should be possible to cross and build on. (Possible, not easy.)
To start, relevant here is Adam's Bridge, a now sunken 50km long and 1km wide land bridge in southeast asia. There is much confusion as to its origin.
Moving on, I'd considered a number of possibilities for how to form this, but I'm learning as I go and don't know enough about to weigh or implement them. This included continental drift, underwater mountains and tectonic plate action, etc. My favorite idea was to make the road part of the rim of an enormous crater. If it worked, this would fit my world really well, as impact events are important to the mythology of the terrestrial culture.