An older chapel was built by Dun Frangisk Depena early in the fifteenth century. However, Bishop Miguel Balaguer Camarasa deconsecrated it on 24th May, 1657 and fell into disrepair. In 1736, Dun Mario Vella caused it to be rebuilt, leaving an annual legacy of five scudi for its maintenance. On 11th April, 1809 the archpriest of Għarb, Dun Publius Refalo, blessed the chapel on behalf of Bishop Ferdinando Mattei. At the start of the second world war, at the request of the procurator Dun Paul Formosa, Papas Schiro` parish priest of the Greek Catholic community, celebrated Mass at this chapel that bears the name of a Greek saint.
There is at San Dimitri a stone altar. The altar-piece, showing St. Demetrius on horseback with a praying old woman and a young man in chains, was restored by the Gozitan artist Wistin Camilleri. The mosaic pavement was laid in 1935, and the walls were coated with mosaic in 1950. Other paintings represent St. Paul, St. Aristarchus (one of his companions in Malta), the Assumption and the Holy Face of Christ. The chapel has a small sacristy and a pleasant “zuntier”.
There are three related legends in Gozitan lore about this westernmost chapel. An old legend relates the liberation from slavery of a young man who lived nearby. An old woman called Natalizja Cauchi and nicknamed Żgugina had only one son named Mathew. One night Barbary corsairs swooped on the island, broke into Żgugina’s house, knocked her down and made away with her son. The unfortunate woman ran weeping to St. Demetrius’ chapel and poured out her heart in passionate prayer. “San Dimitri, bring me back my son, and I’ll light your lamp with a measure of oil.” St. Demetrius heard her supplication. She saw him moving in the painting, whence he rode out and set off in pursuit of the Turkish galley. Soon he was back holding the boy in his arms. Then he reentered the picture frame, but the horse’s hoof mark remained imprinted in the rock. According to another legend, an earthquake toppled into the sea the rock on which the old chapel was built, but the chapel itself did not break up, and sailors and fishermen often said they saw Żgugina’s lamp still burning under water! Another version of the latter part of the legend is that of a ship that dropped anchor close by. The anchor stuck and could not be recovered. Accordingly a sailor dived overboard to try to pry it loose. When he did not resurface, another sailor went to look for him. After a while both sailors surfaced and recounted to the awed crew how on the sea floor they had seen the chapel with the lamp in front of the painting still alight!