Road station
Cortovallio
Heerlen
Cortovallio is Coriovallum, today Heerlen in Dutch Limburg, on the road from Tongeren to Cologne, at the point where it crossed the road from Sittard to Aachen. The map has turned the i of Corio into a t. Older research looked for it at Valkenburg, which is too close to Tongeren, or even at Aachen. A milestone found at Tetz in 1819 counts its miles from Coriovallum. On the map the stretch on to Jülich has no marked start.