On Kalymnos there is total of 23 Paleochristianic 5th and 6th century churches still preserved. The most famous is Christ of Jerusalem, a basilica within walking range from Pothia, on the way to Panormos. It is built in the place where the temple of Apollo used to stand, while some parts of the ancient temple were used to build it. It is worth seeing the sanctuary apse which is in good condition and the mosaic representations of animals in their natural environment.