Hi Mr B,

You can see loads in a day - we've been on the ferry a few times. The first time I think we had a bit longer, but we saw all of the sites featured in Craig Weatherhill's Cornovia (do you have that?)

We walked around the island clockwise, started off with the Harry's Walls standing stone, then on to Bant's Carn (fab), Halangey Down (busiest site of the day, but it was June), Long Rock standing stone, Lower Innisidgen, Innisidgen (both of these are top drawer), Porth Hellick Down and The Great Tomb (also fab), finished off at Buzza Hill, icecream in Hugh Town.

On other trips we've been to see the Deep Point cairns and the Giant's Castle fort and Salakee Down (tombs are overgrown in summer). The sculpted granite on Penninnis Head is truly amazing.

You should have a great time!

By the way, the main (red) roads on the OS map are really just leafy country lanes, so you can take fairly direct routes along them without worrying about being mown down.