Cawsand is one of twin villages (Kingsand being the other) in in southeastern Cornwall.
Take the car Torpoint ferry or the passenger ferry from Stonehouse, Plymouth, to Cremyll and then take an (infrequent) bus, or usually, a boat from the Barbican area of Plymouth across the Tamar. That can lead to a very pleasant day.
The beaches are not large but are still interesting for children, with an old lime kiln and numerous rock pools.
There are good walks botg into the Mount Edgecombe Estate, towards Plymouth, and, the other way, to the wooded headland of Penlee Point and/or to Rame Head.