This pinnacled gatehouse, elaborately decorated in East Anglian 'flushwork', is the sole survivor of the wealthy Benedictine abbey of St John. It was built around 1400 to strengthen the abbey's defences following the Peasants' Revolt.
Later part of the mansion of the Royalist Lucas family, the gatehouse was bombarded and stormed by Parliamentarian soldiers during the Civil War siege.
Read more about the history of the gatehouse.
Managed by Colchester City Council - visit their museum website for more ideas on exploring Colchester's fascinating history.
Before You Go
Opening Times: The exterior can be viewed at any reasonable time during daylight hours. The interior is open occasionally for Heritage Open Days.
Parking: No parking on site but charged public parking, not managed by English Heritage, is available close by. The nearest are Napier Road North and St John's car parks.
Facilities: There are no facilities on site but it is just south of Colchester town centre and close to Colchester Town railway station. There are toilets at the station.
Dogs: Assistance dogs only are allowed in the interior.
Plan a Great Day Out
Colchester is also home to the remains of another medieval religious house at St Botolph's Priory, just a few minutes' walk away from St John's Abbey Gate.
Also in Colchester are the Iron Age defences of pre-Roman Colchester at Lexden Earthworks and Bluebottle Grove.
Head towards the coast and visit Landguard Fort, a 45-minute drive from Colchester. This impressive safe haven defended the approach to Harwich Harbour, and was the site of the last opposed seaward invasion of England by the Dutch in 1667.