Bizerte is located in the north of Tunisia, approx. 65km north of Tunis. It is the the largest city north of the capital. Bizerte is not on the tourist track so you may actually have a chance to see some real Tunisia here. The main other reasons to come here are the unspoiled traditional quarter of the old port and the presence of a couple of good beaches in the area.
The main draw in the old medina is the enormous kasbah. With its massive walls it looks out over the northern side of the entrance to the old harbour. Originally a Byzantine fort built in the 6th century AD, the present fort was built by the Ottomans in the 17th century. There is also a smaller fort called ksibah, which actually also means small fort, which houses a small but interesting oceanographic museum.
Around Place Bouchoucha in the heart of the Ottoman town you find lively fish markets, the Great Mosque and the Youssef Dey fountain. Up on a hill overlooking the town there is the so-called Spanish Fort. As far as I know it’s actually Turkish.