Martello towers are small coastal artillery forts constructed after renewal of war with France in 1803. A total of 103 tower were constructed, those on the south coast were numbered 1-74 and those in Essex and Suffolk were numbered A to Z. These towers were typically circular of near circular in plan and contained three floors and were an average height of 10 metres. They were built of brick and often rendered, and were up to 4 feet thick on the seaward side. The top floor housed cannons and the middle floor served as living quarters for about 25 men. The lower floor houses the ammunition and gun powder.
Tower F is the only remaining moated example on the Essex coast. Out of 29 built on the East coast only 17 now survive, the others having been lost to coastal erosion or demolished.
Completed in 1812, Tower F is now a grade 2 listed building, though the timber clad observation room, originally housing the coastguard is excluded from the scheduling.
The cache is not at the posted co-ordinates but a short walk away. the co-ordinates to locate it are; 51 46.ABC 001 08.DEF
A=Total number of towers originally built -94
B=Average height of Martello towers -2
C=Surviving number of towers on the east coast -13
D=Number of floors +1
E=Maximum thickness of the walls on the seaward side -4
F=Date of renewal of war with France -1797
***Congratulations to clactoncachers for being first to find, and congratulations to Smigguel for being a close second to find***