Ksour Toual is a strange view, being a two storey mausoleum standing out in the fields, all by it self.
The immediate idea you have seeing it, is that it was the mausoleum of a wealthy landlord. But up from the mausoleum lies a few stones indicating that there must have been a city here of some size, which was known as Vicus Maracitanus.
The mausoleum is nice, with an interior where you may notice the many small niches.
In order to get out here, you cannot rely on public transport. This area has very few inhabitants. If you hire a taxi, this is best done from Siliana. Then, of course, you throw in a visit to Zama Minor (9 km off another road) and Kbor Klib, 1 km further from Siliana. The whole trip would be something like 60 km and take about 4 hours. For a full day, include Elles and Zannfour, but with Maktar as the first stop, and Ksour Toual going back. Driving distance would be about 150 km.
Siliana has a hotel and restaurants, as well as good connections to the rest of Tunisia. A second place to start is from Le Kef, but that involves an extra 90 km of driving.