The Temple of Janus is a peculiar sight — two tall sections of Roman masonry, about 24 metres high, standing alone in a field on the northern edge of town, slightly apart from the main ancient monuments. The name "Janus" is a medieval misnomer; the building was actually a Romano-Celtic fanum, a type of tower temple common in Gaul, probably dedicated to a local deity.
The two surviving walls — about one-third of the original square structure — stand free and unexcavated in an agricultural field. There is no fence, no signage, and often no other visitors. The scale of the masonry is more impressive close up than in photographs, and the contrast between the ancient stonework and the surrounding farmland is striking. A ten-minute walk north from the Porte d'Arroux.