Geology and quarrying
The geology of Ham Hill is about 170 million years old and very special.
The golden, honey‑coloured stone you see here is called hamstone. It was formed long ago when this area was covered by warm, shallow seas. Tiny pieces of shells and sea creatures settled on the sea floor and, over time, were pressed together to form layers of rock.
Walking on an ancient seabed
The hamstone layer is quite thin and sits on top of soft sand called Bridport sand. This means that when you walk around Ham Hill, you are walking on what was once the seabed.
A special place for geology
Ham Hill is an important site for studying rocks. Some of the stone outcrops are protected because of their scientific value and are classed as Sites of Special Scientific Interest or Local Geological Sites.
Quarrying at Ham Hill
Hamstone is easy to carve and strong enough for building. The Romans were the first people to quarry stone here on a large scale.
By the 1880s, quarrying was at its busiest, with more than 200 men working at Ham Hill.
Hamstone buildings and clues from the past
Hamstone was used to build many older buildings in nearby villages, as well as famous places like Sherborne Abbey and Montacute House.
Near the Ranger’s Centre, you can see earth mounds left behind from Victorian quarrying. You may also notice deep scratches on some rock faces – these are old tool marks from when the stone was cut by hand.
Find out more
View information about Somerset’s geology on the Somerset geology website and at the Visitor Centre.