The site's massive Roman stone walls were constructed using 'lacing courses' of flat, red Roman bricks to provide structural stability.
Graffiti carved by French prisoners of war into the interior walls of the keep during the Napoleonic era is still visible today.
The castle was used as a royal residence by monarchs including King John, Henry V, and Henry VIII.
St Mary’s Church, located inside the fort walls, is an Augustinian priory founded in 1133.
The castle’s defensive ditch was re-excavated during the Napoleonic Wars to prevent prisoners from tunneling out.
The inner bailey was once used to house a theater for French prisoners during their internment.
The Roman masonry remains largely intact to its original height, a rarity for fortifications of this age in Britain.
The site saw continuous use from the 3rd century through the Victorian era, spanning over 1,700 years of history.
Portchester Castle is the best-preserved Roman fort north of the Alps, featuring walls that enclose an area of nine acres. The site served as a Roman 'Saxon Shore' fort in the 3rd century before being converted into a Norman castle. St Mary's Church, an Augustinian priory, remains active within the inner bailey. The 12th-century keep stands at the northwest corner of the fort, representing significant medieval structural evolution. During the 18th and 19th centuries, the site functioned as a prison for thousands of French soldiers during the Napoleonic Wars. The outer walls retain original Roman D-shaped bastions. It is managed by English Heritage. Archaeological excavations have identified evidence of prehistoric occupation predating the Roman arrival.
The view from the top of the Norman keep looking down across the Roman walls and the harbor.
Walk the full perimeter of the Roman walls for views of the surrounding harbor.
Bring binoculars for birdwatching, as the adjacent harbor is a significant site for coastal wildlife.
Check the tide times, as the path around the water can be affected by high water levels.
Assuming the church is part of the castle exhibition; it is an active parish church with its own operating requirements.
Operating hours are reduced during the winter season; the site may close periodically for site maintenance.
Wear sturdy, comfortable footwear as the ground is uneven, particularly within the ruins and around the defensive banks.
