The Isle of Grain, is in north Kent, England at the eastern end of the Hoo peninsula and, as shown on the first edition of the one inch to the mile Ordnance Survey map (published in 1801), was originally cut off from it by the Yantlet Creek. However, this has long since been drained and so the "Isle" is now a peninsula.
The Isle is bounded to the south and east by the River Medway, to the north by the River Thames, and to the south west by the Stoke Marshes. The island was almost all marshland - the Grain Marshes - until the nineteenth century, these now being restricted to the north west of the peninsula. Historically, only one road bisected the marshes, leading to the one settlement - called Grain, or St James in the Isle of Grain.
Most of the Isle is an important industrial area, home to a large container port and a power station, and was until 1982 home to a major oil refinery. A major airport to serve London was planned to lie just west of the Isle, and the proposal of this project aroused a lot of local opposition.
Since even today a considerable part of the peninsula is marshland it is an important habitat for birdlife. Other attractions on the Isle include Grain Tower, a fort built in 1855 and in use until 1946. It was a centre for the military during World War I, and in 1918 saw Britain's last recorded outbreak of malaria.
The Isle of Grain is also an alternative name for the peninsula's only village, Grain. Wallend is the other settlement, and is almost entirely industrial. The Isle was once home to Port Victoria, built to rival Tilbury on the north bank of the Thames, but it no longer exists, having been cleared to make way for industry.
The Isle of Grain is sometimes confused with the larger Hoo Peninsula, containing villages including Allhallows and Stoke.