Smalls Lighthouse stands on the largest of a group of wave-washed basalt and dolerite rocks known as The Smalls approximately 20 miles (32 km) west of Marloes Peninsula in Pembrokeshire, Wales, and 8 miles (13 km) west of Grassholm. It was erected in 1861 by engineer James Douglass to replace a previous lighthouse which had been erected in 1776 on the same rock.