Ciodaru

Out of all the lost cities, Ciodaru is the least described, as a far smaller group of an already minuscule number have ever actually seen the city and returned. A shock, considering the dangers provided by the location of other lost cities.
Located deep within the heart of Svogan, Ciodaru is said to exist with at the top of the The Stormcrowned Spine. ''Said to" because of the harsh conditions one must brave to reach it's hypothetical position.
The mountain itself is too sheer to climb for mortals or any god that isn't of the mountains or stone, or doesn't have any ability of flight or teleportation. Even those abilities do not guarantee success. There is little to no cover the whole way up, leaving you exposed to the elements for the vast majority of the ten to twelve week journey as there is almost no space for one to set up any sort of shelter. Alongside the elements, the air gets thinner as you go, and most mortals will pass out somewhere after the halfway mark. If you somehow manage to survive the climb, you then have to deal with the eternal storm that makes it's home at the peak. The true final hurtle, being outside the mountain is a death sentence. Constant lightning strikes, high in volume and destructive might than a naturally occurring storm drive away even the most suicidal explorers. 
No, the only route is through the mountain itself. A network of tunnels, seemingly some sort of mine searching for an unknown material, suffuses the mountain's rocks like veins. They follow no pre determined path, crossing over and under and through each other with no determinable plan. There is no 'path' up the mountain, either. Anyone seeking to delve through these tunnels must essentially do so through trial-by-error. The lack of returns from the tunnels have confounded any attempts to map them. Giving the mountain a reputation for tunnels that shifts and twist as you pass. We can't even determine the truth of such statements.
There are almost certainly other dangers within the mountain, but they are deep enough in to have so far avoided codifying. 
All these dangers, and for what? Gold? The Old Gods? History? We don't even truly know if the city exists, all things told.
Yet it still draws people in like flies to honey.

Type

Large city