The main church (Katholikon) of the monastery, that bears the same name, is an edifice built by Ioannis Fragopoulos, the protostrator (military office) of the Despotate of Moreas. It was inaugurated in September 1428 and it is the last large byzantine church built at Mystras. It still operates as a nunnery.
Like the monastery of Our Lady Hodegetria, it belongs to the mixed architectural type of Mystras. It combines the three column basilica with narthex on the ground floor and the cross-in-square church with five cupolas on the upper floor. The architecture of the church presents numerous gothic elements, mainly on the west side and the belfry, due to the close relations established with the West.
The initial wall paintings, dating back to 1430, and can be seen on the upper floor and the roof. They were created by three different painters and they belong to the Palaeologan style of painting. They are very similar to the frescos of Our Lady Hodegetria and Peribleptos and are also influenced by western art. These high quality paintings were probably painted by painters from Constantinople. The ground floor and the narthex wall paintings date back to the 17th – 18th century. Apart from the portrait (1445) of the byzantine lord Manouel Laskaris Chantzikis on the south wall of the ground floor, the rest of the wall paintings are inferior to the frescos of the upper floor.