The Rabot is a late-medieval fortified gate on the edge of Ghent's historic centre, built after the city resisted a siege in the 15th century. Its two round towers and central passage are modest beside the cathedral and belfry, but they give a useful sense of where the old city hardened into defence.
You do not need long here. Work it into a walk along the western side of the centre, especially if you enjoy the rougher edges where Ghent shifts from postcard canals to working neighbourhoods.