The Grotto of Casteret is situated at the top of a scree / snow couloir 670 metres (730 yd) ESE of the Roland's Breach, and has an impressive entrance porch some 50 metres (160 ft) wide, and 15 metres (49 ft) high. After 60 metres (200 ft) the passage opens out into the vast ice-floored Grande Salle, about 70 metres (230 ft) long, 60 metres (200 ft) wide, and 4 metres (13 ft) high. Its floor is a frozen lake of clear ice with a surface area of about 2,000 square metres (22,000 sq ft).