Uplistsikhe is an ancient rock town built on a high rocky bank of the river Mtkvari. It was one of the oldest urban settlements in Georgia, with some structures dating as early as the beginning of Iron age. There is a nice basilica from 9th century, made of brick and stone.
It was abandoned and left to decay around the 14th century after Mongol raids.
The cache is located a few hundred meters from the rock town and is relatively easily accessible. It is located far enough from muggles' eyes. I recommend to find it along with visiting the city, which is definitely worth the entrance fee of 7 lari (2018).
