It is a natural reserve located in the province of San Luis, at about 2.5 kilometres from the locality of Cortaderas and 20 kilometres from Villa de Merlo. It consists of a ravine through which the Cortaderas Stream flows.
To get there, from Provincial Route 1 there is an access road to Villa Elena (which is where the access to Cortaderas is, but on the other side of the road). After 1.7 kilometres you reach a place where you can park and from there you continue on foot. After about 100 metres you enter the nature reserve.
From the entrance, you follow the path that becomes the trail along which you walk through the ravine in a natural environment. It always runs parallel to and at a variable distance from the stream, which has clear water. After 1.5 km (it takes about 30 minutes) you reach the Parrilla Dam.
Then you can continue the hike with an authorised guide for a longer and more difficult stretch to reach the Esmeralda waterfall and further on to the Chorro Grande.