The Castle can be visited
Corfe Castle

In the English county of Dorset lies the ruin of Corfe Castle. It is situated on a hill in the Purbeck Hills.
History+
The origins of Corfe Castle date back to the late 9th century, when an initial fortification was built under Alfred the Great to protect against the Danes. A dark chapter in its early history was the assassination of Edward the Martyr in 978, which plunged England into a period of Viking raids. Around 1090, the Normans began constructing a stone castle at this strategically important site. Under Kings Henry I, John Lackland, and Henry III, the complex was successively expanded. In the 12th century, Corfe Castle successfully withstood a siege during the civil war between King Stephen and Matilda.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: Colin Jackson
This description draws on the facts documented in the linked Wikipedia article; Wikipedia content is licensed under CC BY-SA 4.0. Wording and editing: Mobile History.
Location: 50.6404, -2.0590