Incredible Art Department - It is one of the oldest art and education websites on the Internet. The site began as a showcase for elementary art students in a school in Indianapolis and has grown to serve the international community. - See more at: http://www.incredibleart.org/#sthash.psWf46jd.dpuf
Stones of Stennes
The Cerne Abbas giant, an ancient fertility symbol carved into the chalk hillside. Cheeky, isn't he?!
Google Image Result for http://www.cadover-image-and-video.co.uk/wordpress/wp-content/uploads/2011/02/Yellowmead-stone-circle-Dartmoor.jpg I've not been to this one but it reminds me of the Barbrook circles in Derbyshire.
Make Stalactites and Stalagmites - Could be a fascinating project to leave sitting at the children's desk... Especially if you take photos every day.