A type of gin produced in Plymouth, England by the oldest working distillery in England. Plymouth Gin has a different taste than London Dry gin. Where juniper is always the dominant flavor in London Dry gin, with Plymouth the various flavors are more evenly blended.
Plymouth was the gin that Winston Churchill and FDR used in their martinis, and the first documented martini recipe (dated 1896) called for Plymouth gin.
It also makes a nice Gin and Tonic.