- Old MacDonald's Farm, Porthcothan, between Padstow and Newquay.http://www.oldmacdonalds.co.uk/ Farm attraction with campsite. Near some fantastic beaches and coastline generally but it's north coast and the waves might be a bit offputting for a 3 year old! The beaches won't be though, especially at low tide. We will be going here on 4th July for a night or two (three Mums, three three year olds, and a nearly-one year old) so will review after that.
Parbola, near Hayle. http://www.parbola.co.uk/ Inland so you will have to drive everywhere but near St Ives, near Hayle's great beaches and generally quite central for most of the western end of Cornwall. Also near Paradise Park which is a firm favourite with the boy and his mates http://www.paradisepark.org.uk/
Sea View International, Gorran, near Mevagissey.http://www.seaviewinternational.com/ Gorran is a bit out on a limb if you want to do lots of touring around Cornwall but if you are pretty much staying put it's a lovely area, with some excellent beaches and being south coast it's flatter water so great for paddling and rockpooling.
If you need any more info on how to keep a 3 year old boy occupied in Cornwall (particularly if it's raining) PM me because I've got one, and I will let you know what we get up to in this part of the county. It's my intention in due course to put a general post up on low cost and free activities for kids in Cornwall although I might need a bit of help with the eastern and northern side as news of local events doesn't travel very far in this part of the world. Actually, news doesn't travel across Cornwall very well at all