Isova is the site of a ruined Frankish monastery near the modern village of Trypiti (formerly Bitzibardi) in the western Peloponnese, Greece. The church of Notre Dame at Isova, built in the first half of the 13th century, is among the best surviving examples of Gothic architecture in the Peloponnese, along with the church of Saint Sophia at Andravida and the monastery of Zaraka at Stymphalia. Foundation The Frankish monastery at Isova was founded some time after 1205, when the French Principality of Achaea was created in southern Greece in the wake of the Fourth Crusade, and before 1263, when the abbey was destroyed by fire (see below). Although the religious order responsible for the monastery is not recorded, it is now generally believed to have been a Cistercian foundation. The Cistercians were active in the Fourth Crusade and established at least a dozen abbeys in Byzantine territories captured by the Crusaders, and there is archival evidence that specifically suggests Cistercian involvement in two monastic foundations in the Peloponnese itself during the early 13th century. One of these two Cistercian abbeys in the Peloponnese can be identified with certainty as the monastery of Zaraka at Stymphalia, in the archdiocese of Corinth. For the other, the monastery at Isova, in the archdiocese of Patras, appears to be the only known candidate. Architectural remains Notre Dame The abbey church of Notre Dame consisted of single large rectangular hall, ca. 38.5 m long by 12.5 m wide (internal measurements), with a chancel at the eastern end projecting an additional ca. 8 m and ending in an octagonal apse supported by six external buttresses. The west and north walls are nearly intact; the south wall is partially destroyed and the east end is barely preserved above the foundations. There is no evidence of internal supports dividing the interior into nave and aisles, and no narthex or transept. The triangular gable of the west wall preserves the profile of the steeply pitched wooden roof, which apparently covered the entire width of the main hall in a single span, presumably with trusses, which were supported on simple corbels ca. 4 m apart in the side walls. A reused fragment of rib vaulting built into the wall of the later church of Saint Nicolas suggests that the chancel was roofed with a stone vault. The well-preserved windows in the north wall are single lancets (1.80 m high)