St Honoré

In the novel A Caribbean Mystery, St Honoré is an island in the Caribbean. The capital is Jamestown. Miss Marple stayed at The Golden Palm hotel. Some sights which she considered visiting are Castle Cliff and Pelican Point. St Honoré's climate is described as "not really what is referred to as 'Tropical Heat'". Diana Horrocks, a friend, accompanied Miss Marple as far as Trinidad from whence Miss Marple continued her journey to St Honoré. This is somewhat strange as Trinidad is about the furthest from Britain among the islands, almost off the coast of South America. Perhaps St Honoré did not have a direct air service from Britain and Miss Marple had to transit at Trinidad.

Real life inspiration
One possibility is that St Honoré is based on Barbados where Agatha Christie spent some time, staying at the "Coral Reef Club", believed to be the inspiration for the Golden Palm. Another possibility is that St Honoré is based on St Lucia (which Christie possibly visited). Both the island and the fictional counterpart are named after female saints. The description of the airport is accurate and it does have a direct flight from Trinidad in the 1960s like the one Miss Marple took in the book. St. Lucia really does have a location named Pigeon Point as mentioned in the book.