Martello Tower, Seapoint

The tower a few miles farther south, in Sandycove, is the one Joyce used as the setting for the opening section of Ulysses. It's a museum now. This one, closed for much of the year, gives a good idea of the sturdiness of these structures. Nabokov likened them to a the standard chess castle. They were set up to defend the Empire against the French. They have housed eccentric rock stars and supplied a background for at least one monumental work of literature. Now they proceed with the no less vital work of providing subjects for photographers and Sunday painters, bathing shelters (on the far side), roosts for pigeons and railings for old men to dry their towels and togs on.

Here's a MORE ROUNDED VIEW.