In the novel A Murder is Announced, Medenham Wells is a town not far from Chipping Cleghorn. The Royal Spa Hotel where Miss Marple stayed at at the beginning of the novel is located there. She later moved to the vicarage at Chipping Cleghorn, commuting to Medenham Wells twice a week to continue her spa treatment.
There is a regular bus service between Medenham Wells and Chipping Cleghorn and it appears access is convenient. Mitzi, for example goes to Medenham Wells by the bus on her days off.