On the bottom of a glacial cirque open to the east, under Cima Lastè and Mount Nambino above 2000 m., there are three enchanting lakes called Tre Laghi (upper, medium and lower). They are not far from each other and separated only by a few meters in level.
Of the Tre Laghi the Upper one has steep banks and for the most part consists of groundwater detritus and moraine deposit. Of quadrangular shape, it has a very irregular bottom from which some picturesque rocky little islands emerge, partly green due to the presence of Rhododendron ferrugineum. The area of maximum depth is towards the south. Near the shore a small spring gushes out, which together with another small stream constitute the only surface tributaries. The main emissary is located on the eastern shore and is the inflow of the Medium lake. This small lake, with an elongated shape and a very modest depth of less than two meters, is surrounded by grassy banks. The seabed is muddy, a characteristic that makes it suitable for hosting a large population of amphibians. From here emerges the emissary that reaches the lower lake, the largest and deepest of the three basins, with a rounded shape and extended towards the East.
This lake has unfortunately suffered in the past from the frequent introduction into its waters of fish not originating from this ecosystem. Also for this reason it was thoroughly studied seasonally for a year during a research carried out in the late 90s by the Museo Tridentino di Scienze Naturali on behalf of the Park.