Pick a local place of interest and take the Beavers on a walk to visit it. In our case it was the Folly at the top of Reigate Hill.
A place of interest, some beavers
Do some googling to find out a few facts about the place of interest. Find somewhere convenient nearby to meet up that offers a safe route for the beavers to walk there in about 20 minutes or so (about 0.5km to allow time for headcounts, pauses to look at interesting things etc).
When you get to the place of interest tell the beavers about it and let them have a look around and ask questions. Once you've seen enough, walk back to the pickup point.