Kronstadt still retains some of the "forts", small fortified artificial islands.

A fortified island in the middle of New York Bay.

Look out towards the tiny fortified island of Bourzi; you can even take a boat trip to explore the castle if time allows.

This town stands on two small fortified islands and contains many interesting old buildings and restaurants.

The heavily fortified island was part of the German Atlantic Wall system of defense.

Naos is a fortified island located in Panama Bay.

By now the fortified island of Lagos had become a major centre of the slave trade.

For years, this city was a fortified island, protected, for better or worse, against the influences of the world that surrounded it.

But rain turned many of the Prussian defensive positions into fortified islands.

Only the large fortified island of Corfu held out, and there the defenders were forced back into the main town.