The Cave Monastery of Saint Theodor Stratilat, also known as Chelter-Koba, is a medieval Orthodox monastic complex situated in the Bakhchysarai district of Crimea. The monastery is carved into a cliffside and is associated with the veneration of Saint Theodore Stratelates, a revered military saint in the Christian tradition. Its foundation is generally dated to the period between the 13th and 15th centuries, a time when the Principality of Theodoro, a Byzantine successor state, flourished in the southwestern Crimea. The monastic complex comprises several cave structures, including a main church, monastic cells, and various utility rooms, all interconnected by a system of passages and staircases hewn directly from the rock. The main church features an altar, a synthronon, and niches for icons, demonstrating typical features of Byzantine cave architecture. The monastery was abandoned, likely following the Ottoman conquest of the region in the late 15th century. In the modern era, the site has been the subject of archaeological and historical study, and monastic life has been revived, with the monastery being re-consecrated and functioning as a male monastic community. It represents a significant historical and cultural monument, illustrating the ascetic traditions and spiritual life of medieval Crimea.