Val Curciusa leads south from Nufenen in the direction of the Misox valley, ending at the Bocchetta di Curciusa, a mountain pass, which is visible directly from San Bernardino when looking southeast.
The valley is about 9 km long and is drained by the Areua Brook, which flows into the Hinterrhein at Nufenen.
Although the valley drains to the north part, about 85 percent of the area, until about 2 km from the confluence of the Areua Brook and the Posterior Rhine, belongs to the municipality of Mesocco south of the watershed.
The Curciusa Alta gained national notoriety through a Pump Reservoir Project, which was withdrawn in 1999 for "economic reasons" shortly before a federal court was to decide on an application for environmental protection.
It is only accessible on foot and surprises with a Wild West atmosphere on the second-highest part of the valley, the Curciusa Bassa, where not only cattle but also horses are allowed to graze in summer.