At the western end of Lake Qarun, just east of the village of Qasr Qarun, are the ruins of ancient Dionysias, once the starting point for caravans to the Western Desert oasis of Bahariya. All that remains of the ancient settlement is a Ptolemaic temple, known as Qasr Qarun, built in 4 BC and dedicated to Sobek, the crocodile-headed god of Al Fayoum. There are excellent views from the rooftop.
The temple is built of blocks of yellow limestone, but unusually for Egypt there are no inscriptions, except over the entrance, where there is a winged sun, and on the roof, a headless relief of Sobek on the left and a king on the right. The internal structure has been reinforced; if you are feeling adventurous explore the amazing maze of chambers, tunnels and stairways. Take a torch or candles.