We know we are biased, but we do believe we have one of the most loveliest cycle routes in the UK going around the Exe Estuary.
https://www.exe-estuary.org/web/exe-estuary/exe_estuary_trail
The National Route 2 covers the whole south coast of England and here in Topsham we lie in the middle of the wonderful Exe Estuary Trail - which is part of the NCR 2. You can choose to cycle just a few miles to do the whole route around the estuary using the little ferries. It is all very family friendly with great paths and routes.
Check out cycle routes www.cycledevon.info/cycle-routes/