The Ecclesiastical Museum of Hydra: One of the most interesting places to visit in Hydra is the Cathedral Museum or the Ecclesiastic Museum, which is located above the port. The Ecclesiastical Museum is housed in the church of Assumption, which is also the Cathedral of Hydra. This cathedral was originally built in 1648 and was reconstructed in 1774. For a small period, it also operated as a monastery. The Ecclesiastical Museum contained rare Byzantine icons, clerk relics, and holy gospels.