Lake Como

One of its characteristic features is its shape of an inverted "Y" or the Greek letter "λ".

An excerpt from the article 15 facts about Lake Como

The triangle formed by two diagonal branches of the lake is called in Italian Triangolo lariano" - "triangolo" - triangle, "lariano" - related to Larius, which is the Latin name of Lake Como.

It consists of a peninsula that ends at the village of Bellagio, but can be considered an island because the third side of the triangle (not occupied by Lake Como) is dotted with seven smaller lakes.