Houmt Souq is quite different from any other Tunisian town south of Sidi Bou Said, which could be considered as its lost brother. One of the great things about Houmt Souq are the funduqs that have been hotels (and more) for sometimes hundreds of years. The still run after old patterns, few accomodities have been added, but at a price of maximum US$10 each per night, you're in for a memorable experience. I myself stayed in a hotel, with vaulted rooms, shaded by a chalk-white arcade, and with doors facing the atrium that was full of green plants and red flowers, and a small pool in the middle. This atrium was a restaurant with traditional music performed live every evening. One of those things you never forget. The upper picture is from this hotel, the Arischa.
Houmt Souq holds a nice little church lying just between Hotel Arischa and the Mosque of the Turks (picture higher up). There is still performed services here, but the church is now mostly used for non-religious activities among Jerban youth. The other noticeable mosque in Houmt Souq is the Mosque of the Strangers (just above). Down by the sea side, the fort Borju l-Kabir, has admission and is well worth the walk down from town centre.