There's a program on iplayer at the moment called 'The Code' all about numbers and how they relate to nature and the universe etc. The presenter wanders around Swinside circle with a tape measure to explain about Pi with some nice moody and atmospheric shots of the stones from about 25 minutes in.
Elsewhere, if you ever wondered what happened to Velma from Scooby Doo then watch the bit about nautiluses :-)
http://www.bbc.co.uk/iplayer/episode/b012xppj/The_Code_Numbers/
-Chris