Rising from the edge of the Kura River in the depths of south Georgia's borderland summits, the slopes of Erusheti Mountain hold one of the great ancient treasures of the Caucuses: the Vardzia Monastery. It's the kingpin of a whole region that draws explorers with the promise of deep canyons and craggy ridges, mysterious Christian shrines, and intriguing troglodyte architecture. When completed, this underground fortified monastery dug down to 13 levels with 6000 apartments, until an earthquake ripped it apart a century later.

Most Vardzia tour guides will offer day-long or two-day trips through the area out of nearby Aspindza or even Borjomi. Be ready with the camera the moment you depart, though – the journey is breathtaking. You will cross the gushing Mtkvari River, glimpse the fir-clad slopes of the Lesser Caucasus, and spy time-stood-still highland villages like Pia and Toloshi as you go.

In Vardzia itself, the Church of Assumption is the piece de resistance. Scrawled in 12^th-century frescos and decorated with gold-tinted iconostasis, it's entirely cut from the rocks of high-perched cliffs. Around that spreads a whole ridge of deep caves and cave homes, where some monks still live and meditate to this day.