Which caves in our world are worthy of being dungeons and how would you do them, in a gaming system of your choice?
I've used undergalcial river caves in my most recent D&D game... but I don't think in terms of the real world ones when doing dungeons, as I associate dungeons with intentional maze-like constructs (fantasy), and prisoner cells beneath castles (Historical).
That said, some of the Welsh coastal cave homes would make decent 5-room dungeons...
on a larger scale, the abandoned city of Petra is a great valley village carved into the sides...
See, what makes a cave a good place for either a fortified dwelling, camouflaged fortress, or prison is defensibility... and access to food, water, and resources.
The Cappadocian cave cities are poor dungeons - they're defensible, sure, but mostly from the surface; some interconnected underground. Some of the ones in above ground outcrops are still inhabited. A few are rumored to have new digs happening on a family by family basis.
The Ethiopian and Tunisian underground compounds (one of which is highlighted in Star Wars...) are villages/cities (Tunisia) or church, rectory, parish "hall," and monastery compounds (Ethiopia and Eritrea), noted for plenty of light but low direct insolation, and thus comfortable temps all the time. The issue with these is multifold - the biggest being rain. They're a single pit, and human-excavated rooms off the center. If used as such, a desert "well town" makes a great adventure location, but not really a dungeon in the classic maze sense of D&D use.
The Polish Salt Mine dwellings and churches are there because salt was more valuable than silver until the 18th C... and the rise of evaporative salt mining from the ocean on a practical scale. They have no food source; it's traded for. Likewise, water isn't a thing you can find in them - the salt is hygroscopic, so water is also imported... the churches and dwellings were present because of the travel times; house the workers near the working faces, provide them a church, and give them water and food rations in exchange for the salt... This also means, however, that they are not good dungeons, as they can't sustain life without support from the surface, and a dryness so profound it's used medicinally...
Oh, and I do heartily recommend use of Jennel Jaquays'
Central Casting: Dungeons, published under the name Paul Jacquays. Hard to find, but VERY worth it.
Some links:
More than 85m beneath the famous fairy chimneys of Cappadocia lies a massive subterranean city that was in near-constant use for thousands of years.
www.bbc.com
Located about 40 kilometers from the oasis of Gabes, Sidi Driss is set in a rugged, arid environment that was deemed the perfect location for the filming of Star Wars Episode IV: A New Hope. A visit to Matmata, Tunisia, will take you through both movie history and a cultural introduction to the...
www.uniqhotels.com
www.wmf.org
Petra, Arabic Baṭrā, ancient city, centre of an Arab kingdom in Hellenistic and Roman times, the ruins of which are in southwest Jordan. The city was built on a terrace, pierced from east to west by the Wadi Mūsā (the Valley of Moses)—one of the places where, according to tradition, the...
www.britannica.com
Inhabited since prehistoric times, this Nabataean caravan-city, situated between the Red Sea and the Dead Sea, was an important crossroads between Arabia, Egypt and Syria-Phoenicia. Petra is half-built, half-carved ...
whc.unesco.org