Based in South Kensington, you can gain entry via the tunnel to the museums. It offers activity packs for children (which take about an hour to complete). They go around the museum hunting for clues and it's a lovely way to learn. Very visual, lots on display. We were there for about 3 hours, did 2 activity packs and went with our 2 and 6 yo to the childrens activity room, where they made a Winne-The-Pooh poster and had their lunch in the lunch room. There are a few cafes on site - one outside in the courtyard. It comprises of a few floors - I think 5 in total. We would go again in a heartbeat.