About
Upnor Castle is a Tudor artillery fortification on the west bank of the River Medway in Kent, built between 1559 and 1567 during the reign of Elizabeth I to protect the anchorage at Chatham where the warships of the Royal Navy were moored. Today managed by English Heritage, the castle survives remarkably intact and offers visitors a compelling encounter with Tudor military architecture and the naval history of one of England's most important maritime rivers.
The castle was constructed in response to growing concern about the vulnerability of the Chatham anchorage and the expanding Royal Dockyard at Chatham, which by the Elizabethan period was becoming the principal base for the Queen's warships. The design, attributed in part to Richard Lee and others in the Office of Works, combined elements of the earlier Henrician coastal forts with an arrangement adapted to the specific demands of the Medway site. The result was a water-gate fortress with a projecting wharf and platform guns designed to rake attacking vessels with fire as they attempted to pass upriver.
Despite this purpose, Upnor Castle is most famous for a catastrophic failure. In June 1667, during the Second Anglo-Dutch War, a Dutch fleet under Admiral Michiel de Ruyter launched a daring raid on the Medway — one of the most audacious and successful naval operations in European history. The Dutch ships broke through the defensive chain stretched across the river, sailed past Upnor Castle and its guns, and destroyed or captured several major English warships at anchor, including the flagship Royal Charles, which was towed back to the Netherlands as a trophy. Upnor Castle's guns proved unable to prevent this humiliation, and the raid ended the Second Anglo-Dutch War on terms favourable to the Dutch.
Following the Medway disaster, Upnor Castle was converted from a front-line fortification into an ordnance and powder magazine, serving as the principal ammunition store for Chatham Dockyard for over two centuries. Much of the architecture visible today dates from this later phase, including the substantial storage magazines that were added in the 17th and 18th centuries. The castle continued in use as an ordnance depot until 1945, making it one of the longest continuously used military structures in England.
Visitors today can explore the Tudor water-gate, the surviving bastion defences, the great hall and residential range, the powder magazines, and a series of displays covering both the original Tudor castle and its later naval history. The site offers outstanding views across the Medway towards Chatham Historic Dockyard, providing an ideal context for understanding the strategic importance of this location.
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Plan Your Visit
⏱️ Recommended Visit Duration
💡 Visitor Tips
- Combine Upnor Castle with a visit to Chatham Historic Dockyard across the river for a full day of Royal Navy and Medway history.
- The waterfront at Upnor offers excellent views across to Chatham Dockyard — bring binoculars if you have them.
- Check the English Heritage website before visiting as the castle is closed on Mondays (except bank holidays).
- Parking in Upnor village is very limited — consider arriving by bus from Rochester or Strood.
- The castle has multiple levels — wear comfortable footwear as there are steps and uneven surfaces throughout.
- Allow at least 90 minutes for a thorough visit including the powder magazines and all displays.
- English Heritage members visit free — a good reason to invest in membership if visiting multiple EH sites.
- Visit the Upnor village waterfront and pub after your castle visit for a pleasant end to the day.
Highlights
The Dutch Raid on the Medway, 1667
Upnor Castle's place in history rests largely on the events of June 1667, when a Dutch fleet commanded by Admiral Michiel de Ruyter launched one of the most audacious naval operations in European history. The Dutch ships broke through the defensive chain stretched across the Medway at Gillingham, sailed upriver past Upnor Castle's guns, and proceeded to destroy or capture several of the largest warships in the English navy — including the flagship Royal Charles, a 100-gun ship of the line that was towed back to the Netherlands as a trophy and put on public display.
The Upnor Castle garrison managed to fire their guns but were unable to prevent the catastrophe.
The raid effectively ended the Second Anglo-Dutch War and forced England to accept the Treaty of Breda on terms highly favourable to the Dutch. It remains one of the most complete and humiliating defeats suffered by the English navy.
Tudor Water-Gate and Artillery Platform
The heart of the original Tudor fortification at Upnor is the water-gate and associated artillery platform facing the River Medway. The water-gate provided access to the castle from the river, and the guns mounted on the platform and on the adjacent bastions were designed to create a barrier of fire across the river that any hostile vessel would have to pass through to reach the anchorage above.
The Tudor stonework, including the original gate archway and the lower courses of the waterfront defences, survives within the later fabric of the castle and can be examined by visitors.
The relationship between the castle's position, the river, and the opposite bank — where Chatham Dockyard still stands today — is immediately legible from the waterfront, and the strategic logic of the site becomes clear.
The Great Hall and Residential Range
Upnor Castle was not purely a military installation — it also provided accommodation for its garrison and for the officers responsible for its administration. The principal residential range includes a great hall and associated chambers that date from the original Elizabethan construction and reflect the dual function of the castle as both a fortification and a habitable residence.
The great hall is now used to display interpretation covering the castle's history, and the interiors provide a sense of the domestic and social life of the garrison alongside the military function of the site.
English Heritage displays in these spaces cover the castle's evolution from a Tudor artillery fort to its later role as a naval ordnance magazine.
Powder Magazines and Ordnance Store
After the disaster of the Dutch Raid in 1667, Upnor Castle was converted from an active front-line fortification into an ordnance and powder magazine serving Chatham Dockyard. The substantial storage magazines that were constructed during the 17th and 18th centuries for the safe storage of gunpowder and naval ordnance remain among the most complete surviving examples of their type in England.
These buildings — massively constructed to contain accidental explosions, equipped with copper fittings to minimise the risk of sparks, and arranged to facilitate the safe handling of dangerous materials — are a fascinating piece of industrial and military history.
The castle continued in this role until 1945, giving it a continuous history of military use spanning nearly four centuries.
Collections
Upnor Castle's displays cover the history of the site from its Tudor foundation through the Dutch Raid of 1667 and its subsequent use as a naval ordnance magazine. Displays include models, original artefacts from the castle and the wider Medway area, maps, and documentary evidence covering the Elizabethan navy, the Anglo-Dutch Wars, and the history of Chatham Dockyard.
The castle buildings themselves — the Tudor water-gate, residential range, and later powder magazines — are the primary heritage assets.
Tudor Fort to Naval Magazine
The main interpretation sequence traces the history of Upnor Castle from its Elizabethan foundation to its final closure as an ordnance depot, with particular emphasis on the Dutch Raid of 1667.
📍 Great hall and residential range
The Dutch Raid on the Medway
Dedicated displays on the events of June 1667, including the Dutch fleet's breakthrough, the destruction of the English warships, and the aftermath of the raid for English naval policy.
📍 Great hall
Current Exhibitions
No current exhibitions. Please check the museum website for updates.