Meeting point for the participants in Nemi in Piazza Umberto I and start trekking with a guide, following a path halfway up the hill in the crater of Lake Nemi. The route is interesting from a naturalistic, landscape and archaeological point of view because there are several filtering tunnels that were used in antiquity as points for interception and collection of water that served as a water supply for the Municipality of Genzano. You then return to the starting point.

The route lasts about 3 hours. Minimum 6 persons, only on sunday.