The nunnery of Kalamata, in the historic city centre, was built in the late 18th century at the site of an older church that was the katholicon of a monastery. It is a single aisle timber-roofed church with successive building phases, dedicated to Agioi Konstantinos and Eleni (Saints Constantine and Helen). A small part of the original, 12th century masonry has survived in the apse and the south wall of the church. It is built with cloisonné masonry with striking ceramoplastic decorative elements.

The original building has close affinities with Agioi Apostoloi in Kalamata, indeed it might have been the work of the same construction workshop. At a later period, possibly during the second Venetocracy (1685-1715), the church was extensively modified. It was burned down in 1825, during the Greek revolution (1821-1828), and was repaired in the mid- 19th century. The narthex is a later addition.