Actual megadungeon

Undermountain. Castle Greyhawk. Rappan Athuk. IKEA. What is this hobby's fascination with megadungeons? In any case, here's images of a real life megadungeon I found lurking in a bookmarks folder. Head ye to Turkey and dig (haha) Derinkuyu, Kaymakli or the other underground cities of Cappadocia. Just don't forget the garlic.