Bassin Blanc is an old volcanic crater found in the mountain range of Savanne of the south west of the island. It is easily accessible by road from La Marie road going towards Chamouny.
The edge of the crater is close to the road side but can readily be missed. The crater itself is about 350 metres wide, 50 metres deep and the bottom of the crater is 250 metres wide. Bassin Blanc is 500 metres in altitude and the air can be refreshingly cool. At the bottom a small lake can be seen.
A small foot path leads down to the bottom of the crater but care must be taken as the way down can be slippery. The lake at the bottom is fed from rain water mainly and so tends to be marshy and an ideal breeding ground for mosquitoes
source: Institute For Environmental and Legal Studies