towers round around derry city

Martello towers get their name from a place in Corsica named Mortella where there was a round tower which proved impregnable when attacked by the English in 1794, twenty-six years after Napoleon's birth on the island.

When, in 1804, it looked as if he might turn the tables and invade England, the English built similar towers around the coast of Ireland which, they feared, Napoleon might use as the 'back door' to England. Though the fears proved groundless, the towers still stand as a m...