The two small villages of Kingsand and Cawsand used to mark the border between Devon and Cornwall. Over the years, they have merged into one and lost their border status but they've retain their charm as quintessential Cornish fishing villages.
When I visited the area around Whitsand Bay in July this year, I made a couple of visits to Kingsand and Cawsand. We arrived the boring way, by car, but you can also get a small passenger ferry from Plymouth Hoe in the summer. The ferry drops the passengers off right on the beach, requiring a proper gang plank to avoid wet feet.
Both villages have small beaches, which can get busy on a sunny day but when quiet, have plenty of space for building sand castles.
The villages are definitely worth a poke around, the streets are narrow and windy with some striking buildings and the walk between the two villages offers great views out to sea. The point that marked the border between Devon and Cornwall is still marked with an ancient sign.
When you are done looking around, I really recommend stopping for a drink and some food in the Devonport Inn in Kingsand. They do some great seafood and the staff were very friendly when we visited.