Nicodemus Knob

Nicodemus Knob is a lone stone pillar about 9 metres (30 ft) tall on East Cliff, on the Isle of Portland in Dorset, England. It is made of Portland stone and stands on the rim of the island's plateau, high above the sea. Quarrymen left it behind, and it has become one of Portland's best-known landmarks.

What is Nicodemus Knob?

The knob is an artificial stack. Nobody carved it as a monument in the usual sense. It is a block of unquarried rock that remained when the surrounding stone was cut away. Dorset's Historic Environment Record describes it as a pillar of unquarried stone left from deeper quarrying in the mid-19th century. The structure first appears on an Ordnance Survey map from 1889.

It belongs to the former Admiralty Quarries. These quarries supplied stone for the breakwaters of Portland Harbour between 1849 and 1872. Convicts did much of the excavation, and about six million tonnes of rock were removed. The pillar marks how high the ground once stood before the work began.

Why was the pillar left standing?

The original purpose is uncertain, and sources offer several explanations:

• a seamark visible from the water,
• a memorial to the quarry workers, or to the convicts who died there,
• a marker of the original ground level.

The Portland Museum archive favours the idea of a memorial to the prisoners. No single explanation is confirmed.

What is nearby?

Pulpit Rock at Portland Bill is a similar pillar formed by quarrying, though it sits at the far southern tip of the island. Close to Nicodemus Knob, above East Cliff, Dorset's heritage records also list a boundary stone. It is marked with a War Department arrow, an anchor and the number 61.

Climbing and the changing landscape

Climbers know the knob as a squat pinnacle above the sea, and it appears in the UKClimbing crag database. The quarry floor below the cliffs has been filled in. Most of the former 15 m drop has therefore disappeared, and the pillar now looks lower against its surroundings than it once did.

Tips for visiting

• The knob stands near the edge of the plateau. Keep a safe distance from the cliff edge, especially in wind.
• Combine it with a walk around East Cliff and the old quarry landscape, which is full of cut blocks and industrial remains.
• The island is exposed, so take a windproof layer even on sunny days.
• Good light for photos comes in the morning and late afternoon, when the pale stone stands out against the sea.

Frequently asked questions

How tall is Nicodemus Knob? About 9 metres (30 ft).

What is it made of? Portland stone, the limestone quarried on the island for centuries.

Who built it? No one built it. Quarry workers left it standing while stone was cut around it in the 19th century, and convict labour did much of that work.

Why does it exist? The reason is not documented. Proposed explanations are a seamark, a memorial or a ground-level marker.

Is it similar to Pulpit Rock? Yes. Both are pillars left by quarrying on the Isle of Portland, but Pulpit Rock is at Portland Bill and Nicodemus Knob is on East Cliff.