I am taking inspiration from games like Dark Souls (Dark Souls 1: Lost Izalith, Dark Souls 2: Shulva - Sanctum City, Dark Souls 3: Profaned Capital) and Elden Ring (Eternal Cities - yes it is underground and the ceiling is illuminated by light-bugs), where the player can sometimes make his way to entire cities that are buried underground or are found inside giant caves that have seemingly formed around the city. Weirdly enough, the city layout, roads and buildings are sometimes left intact. Additionally, on top of the city, in the surface, the people are either completely oblivious to its existence or consider it to be ancient ruins or a long lost city of some legend.
What are ways that cities can end up buried deep underground (~100 or more meters in depth) but remain intact and retain their general layout?
Could this be possible in real life?