Gravesend Blockhouse

Gravesend Blockhouse is a D-shaped fortification built from brick and stone with a circular bastion that overlooks the River Thames. Gun platforms extended from this structure toward both east and west to provide covering fire across the water.

King Henry VIII ordered construction of this artillery fortification in 1539 as part of a broad plan to protect the Thames against invasion. The blockhouse was built during a period of heightened military tension with France.

This structure represented England's first coordinated river defense system and shows how Tudor authorities used military architecture as a strategic tool. Visitors can still sense the importance this fortification held for protecting the nation's waterways.

The archaeological remains are located near the former Clarendon Royal Hotel and marked as a scheduled ancient monument. The visible foundations can be examined from the surrounding area without special access requirements.

In the early 1700s, the fortification stored thousands of barrels of gunpowder and shifted from active defense to becoming a major ammunition depot for the Thames. This transformation made it a critical supply facility for naval operations across the region.

GPS coordinates: 51.44463,0.37277

Latest update: December 14, 2025 11:05