In a beautiful sun drenched gorge, overhung by Monte Zerbion (2719m) at an altitude of 549 metres, Châtillon extends across a vast gorge on two of the Dora Baltea slopes and the Marmore river, with the Monte Zerbion to the north and the Barbeston and Cima Nera to the south.
The town grew up at the entrance to the Valtournanche, partially perched on the river banks and partly at the foot of the hill where the parish church and castle stand.
The large village of Chameran, on the other hand, grew up entirely on the right bank of the river Marmore.
Over the last thirty years, considerable building work has been done that has swept over vast areas of the hillside and “plain”.
Already inhabited in the pre-Roman era, undoubtedly by a Roman settlement, in the Middle Ages, it became a rich fief belonging to the Challant nobles who left important traces.
It has a modern sports centre and a renowned hotel and catering school.
The town preserves a group of houses from the XVI and XVII centuries. In some villages, well preserved groups of rural houses and numerous Medieval towers can still be seen (Conoz, Néran, La Tour). It is located in correspondence with where Valtournenche merges with the Central Valley.
There are three castles that stand out on the Châtillon landscape. As well as the already mentioned Challant castle, there is also the Baron Gamba castle, immersed in a vast park, future home to the regional picture gallery and the Ussel, to be found just beyond the Dora and built by Ebalo of Challant in 1350. It was carefully restored and nowadays is used for temporary exhibitions in the summer months.
The daunting bridge over the river Marmore is monumental and dates from Roman times with a spectacularly huge single arch. Thanks to an arch that survived there are remains of another Roman bridge over which passed the Roman consular route.