Sanctuary
Actual photo of ruins of Vardzia, in the country of Georgia. There were at one time six thousand separate chambers, a vast hollowed-out mountain fortress, a sanctuary against the invading Mongols. It held well... even surviving (after a fashion) an earthquake that sent two-thirds of the underground city falling into the valley below. In time it would fall to the Persians.
There has always been call for sanctuaries - places of refuge not only for lives but for the meanings of life- knowledge, faith, culture and of course the more mundane means to support life.
The thing with sanctuaries though - the almost always end up like Vardzia or some of its more famous cousins, such as Macchu Piccu or Masada. Because they are never made nor sought in times of ease, rather in hardship.
And those who would prefer there to be no sanctuary almost always come looking.