A Martello Tower is a small defensive fortification built in the 19th century, primarily along the coasts of Europe. These towers were designed to protect against naval attacks and were named after a specific tower in Corsica that played a role in the British victory during the Napoleonic Wars. Typically round in shape, Martello Towers feature thick stone walls and a flat roof, often equipped with cannons. They were strategically placed to provide a clear line of sight for spotting enemy ships and to serve as a lookout point for coastal defense.