Although it in no way compares to the splendour of Djemila, the Roman town of Tiddis makes a great day trip from Constantine. The guardian will appear at your arrival to sell you a ticket and may want you to pay for guiding services. Drinks and snacks are sometimes available, but you should be sure at least to bring your own water in summer. There was a settlement on this site from early times, at least since the Neolithic Berbers, but it was the Romans who developed Castellum Tidditanorum, which, as its name suggests, was a castellum or fortress, one of a series of fortified villages that surrounded the larger settlement at Constantine (then Cirta) and protected its territory. Excavations began in 1941 but have not been touched since 1969. Perhaps it required Roman genius to understand how to develop the site, on the slope of a hill near the gorge of Khreneg, carved by the same Oued Rhumel that moulded the landscape around Constantine. The Romans arrived during the age of Augustus, but built much of what can now be seen in the 3rd century AD, adapting their fundamental rule of town planning – two straight central streets that cross at the heart of the community – to the curves of the site. Tiddis had no water sources, so one of the most interesting features of the houses here are the channels and cisterns. They were designed to preserve the rains that fell, on which the community depended during the long, hot summers. From the car park you are greeted by rock, striking red earth and the remains of several circular tombs, some of which are pre-Roman. The main entrance to the village is a classic Roman arch made of massive stones. You can still see where the gate hung and was locked, even this far out into the countryside. Much of what lies beyond the gate – houses; sanctuaries to the Roman gods Ceres, Vesta and Mithra; a solar god of Persian origin; olive presses; and later Christian baptisteries – are little more than ruins, but there are still fascinating traces to be seen. The cisterns can still be clearly seen on the upper part of the site: three large basins flowing into each other; between them they could hold some 350,000L of water. On the lower side of the site, the large ‘Villa of Mosaics’ is marked by the pair of columns flanking its entrance, and here you can make out mosaics, the remains of an olive press, and baths that were later used as a pottery. Above the site, but still on the flank of the hill, there is a cave heated by thermals (which is welcome in winter but you might want to avoid it in summer). The summit of the hill is topped with a sanctuary, originally dedicated to old African gods, rededicated by the Romans to their corn god Saturn, appropriate in a place where agriculture was so important. The turn-off to Tiddis is signposted off to the left, 27km north of Constantine along the Jijel road. The site is another 7km from the sign, along a narrow road, which should be drivable throughout the year. There is no public transport to the site. You could take a bus or collective taxi from Constantine heading to Jijel, and jump out at the appropriate place, but you are unlikely to find return transport. So if you don’t have a vehicle, the surest way is to arrange a private taxi from Constantine. The return trip, including an hour or two at the ruins, is likely to cost around DA1000.