The ruins of two towers, one almost standing to its original height, and some of its curtain wall are all that remain of Hadleigh Castle, overlooking the Thames estuary and Essex marshes.

The construction of the castle began in 1230. It was built for Hubert de Burgh, who had been Chief Justiciar to King John and had acted as regent for the young King Henry III. Hubert's relationship with the young Henry did not remain amicable and Henry confiscated Hadleigh Castle. Henry continued the building work and substantial additions were made in the mid 14th century by Edward III, it is these later additions that are most visible today.

It became the custom for Hadleigh to be granted to a tenant for life, reverting to the King on their death. By tradition the tenants were usually the king's consort, most notably belonging to three of King Henry VIII's wives - Catherine of Aragon, Anne of Cleves and Catherine Parr. In 1551, King Edward VI sold the property, allowing its stone to be used for other building projects.