Fitzwilliam Musuem in Cambridge, is a museum full of valuable collections of beautiful paintings from all over the world.
If you are an art lover, this will be a second home to you. I went there the other day and was in awe of how beautiful the museum itself was and the items they have.
It has paintings, furniture and old armour from all over the world. Even if you are not an art lover, its worth a walk through plus the admission is free. They have e-guides available to guide you for your visit.
They also have a cafe inside or if the weather is nice you can sit outside and have a nice cup of coffee.
I will go back again to have a proper walk through but I would say that it takes at least 2 hours to properly visit.