Saint Sophia (Agia Sofia)
This is the small chapel that is built next to the main church.
This was the monastery's cathedral church, and it preserves in its sculptures the initials of its founder, the first Despot of Mystras Manuel Kantakouzenos (1348-1380). The monumental scene of Christ in the sanctuary apse is among its most impressive paintings.
(Description copied from the official UNESCO leaflet available to the public)