If you like shopping, take time out to go to Gloucester Docks when in Gloucester. You can also discover the museums and cathedral in the area— your sightseeing tour starts here. It's also full of great shops and restaurants, so you can spend the afternoon having a wander. Splash some more cash at Gloucester Quays.
If you want to see the cathedral in Gloucester, head to Gloucester Cathedral, in the centre of town. You could also start your cultural experience by heading over to the museums in the area.