Article snapshot taken from Wikipedia with creative commons attribution-sharealike license.
Give it a read and then ask your questions in the chat.
We can research this topic together.
The Lac de Creno is in the Monte Rotondo massif at an altitude of 1,310 metres (4,300 ft).
It is in the Orto commune of Corse-du-Sud to the north of the 1,511 metres (4,957 ft) Monte Sant Eliseo.
It is drained by the Ruisseau de Creno, which flows south to join the Fiume Grosso, a tributary of the Liamone river.
It is a glacial lake, partially covered by water lilies and surrounded by a forest of laricio pines.
It is fairly easy to reach by foot from the village of Soccia at an elevation of 1,000 metres (3,300 ft), and is busy in summer.
Reille, M.; Gamisans, J.; Andrieu-Ponel, V.; de Beaulieu, J.-L. (February 1999). "The Holocene at Lac de Creno, Corsica, France: A Key Site for the Whole Island". New Phytologist. 141 (2): 291–307. doi:10.1046/j.1469-8137.1999.00343.x.