The Towpath Trail is a circular walk of about 3km, it takes you along the Wareham Causeway, through Ridge, past Redcliff and then back along the Towpath to Wareham. There are plenty of places to park in Wareham but the Quay is the closest (There is is a small fee and you can't park there on Saturdays.)
This cache is placed in lovely location overlooking the gardens of the Priory Hotel.