From Heritage Daily:
Archaeologists have helped to prove the size and thus the importance of a Palace that formed the royal heart of Sherwood Forest in the medieval period, by discovering and excavating the previously unknown boundary ditch of the site.
The ruins of King John’s Palace in Kings Clipstone are a local landmark famous for their association with ‘Bad King John’, the enemy of Robin Hood.
In fact during the medieval period the site was known as the King’s Houses and was an extensive royal palace with an adjacent deer park, located at the heart of Sherwood Forest. The palace was favoured by the crown and visited by all eight monarchs from Henry II to Richard II from the second half of the 12th century until the end of the 14th century.