The visit to the Caves
The Cuevas del Drach were already known during the Middle Ages and were explored in 1880 by M. F. Will and in 1896 by E.A. Martel, who discovered the cave containing the lake that bears his name.
Between 1922 and 1935 the cave was conditioned to be visited by opening a new entrance, building paths, stairs, etc. and, above all, by installing electric lighting designed by the engineer, Mr. Buigas.
The tour takes about an hour, the length being about 1,200 metres, and includes a classical music concert and a boat trip across Lake Martel.
More information you can find here.