I love Cornwall. I have been there many times and planning to go there this August again :)
I love walking... superb views are when walking along the coast from Land's End to Porthcurno beach and Minack theatre (it an amazing walk; approx 15km, difficulty: easy).
Or you can walk from Penzance to St Michael's Mount (again easy walk along the coast, approx 7km).
Check some photos here: https://plus.google.com/photos/101114789248574649486/albums/5197609411689959761?banner=pwa
Enjoy Cornwall :)
Cornwall (where to go, what to do)... http://www.mintytrips.co.uk/cornwall.html almost 8 years ago