| Grain Tower | |
|---|---|
| Grain, Kent, England | |
 Grain Tower at low tide | |
  Grain Tower | |
| Coordinates | 51°27′06″N 0°43′53″E / 51.45168°N 0.73125°E |
| Type | Fortification |
| Site information | |
| Owner | Private owners |
| Condition | Poor condition, derelict and decaying |
| Site history | |
| Built | 1848–55 |
| Built by | United Kingdom |
| In use | 1857–1956 |
| Materials | Concrete, granite, brick |
Grain Tower is a mid-19th-century gun tower situated offshore just east of Grain, Kent, standing in the mouth of the River Medway. It was built along the same lines as the Martello towers that were constructed along the British and Irish coastlines in the early 19th century and is the last-built example of a gun tower of this type. It owed its existence to the need to protect the important dockyards at Sheerness and Chatham from a perceived French naval threat during a period of tension in the 1850s.
Rapid improvements to artillery technology in the mid-19th century meant that the tower was effectively obsolete as soon as it had been completed. A proposal to turn it into a casemated fort was dropped for being too expensive. By the end of the 19th century the tower had gained a new significance as a defence against raids by fast torpedo boats. It was used in both the First and Second World Wars, when its fabric was substantially altered to support new quick-firing guns. It was decommissioned in 1956 and remains derelict today. The tower has been privately owned since 2005 and was reportedly sold to a new owner in 2014 for £400,000.