From Tabarka it's very convenient to travel north of Tunisia: for example, to visit Ain Draham - "Tunisian Switzerland" with magnificent cork and coniferous forests and houses with red tile roofs. Not far to Bizerta, a colonial port with Russian destiny.
Also the city of Tunis - Carthage - Sidi Bou Said is organized. Some tour operators offer a northern archaeological route through Roman ruins (Dugga - Bella Regia - Shetmu - Tuburbo Majus). In principle, you can go to the Sahara, but you need to be prepared for a long transfer.