To the west side above Hohlakas beach, excavations in 1998 revealed the complex of the early Christian church of Ayia Triada (Holy Trinity) with outbuildings to the north and south. The three-aisled basilica with three semicircular apses at its east end has also a narthex to the west. Ayia Triada was built during the first half of the 6th century A.D. and was demolished by the earthquake of 554 A.D. Later, during the Middle Byzantine years, an attempt was made to convert the eastern part of the central aisle in a small chapel, as evidenced by subsequent sections of masonry.
Source: www.kalymnos-isl.gr