The culture is what makes Gloucester, Gloucester! The cathedral gives the city its 'status' and is very impressive, and probably the reason it was used in Harry Potter and The Chamber of Secrets. Concerts and lectures regularly take place here so check their schedule while planning your stay in a Gloucester lodging.
Gloucester Docks and its lifting bridge provide a lovely dip into the history of the city's waterways. The Waterways Museum gives you more of an insight. The docks are constantly full of colourful river boats all year round, but once a year there is a Tall Ships festival where the docks are full of Victorian ships (aka pirate boats!) with live demonstrations – and this event is perfect for kids too. The docks have been updated and are known as 'the Quays' now but it still has the original factory buildings.
Outside of Gloucester, Littledean Jail is a 200 year old prison serving as an interesting museum. There is also Puzzlewood, a woodland which was featured in Star Wars and also served as the inspiration for The Lord of the Rings.