A large stag shape on the valley wall is a scheduled ancient monument and is one of two stags hill figures in the United Kingdom, the other being at Mormond Hill in Scotland. But it is in fact a lead mining waste feature which merely resembles a stag and is not a true hill figure. The spoil from the Gelli mine was initially poured down the valley side to form the 'head and horns'. When the mine reopened at the turn of the 20th Century for zinc production, a tramway was built along the base of the original spoil and across. The dumping of spoil from this venture, created the body and legs.