Star forts, or bastion forts, are a type of fortification that first emerged more than 500 years ago in response to the growing power of cannons on the battlefield, with sloped walls and angled bastions that allowed defenders better coverage above any attackers. These polygonal or star-shaped defensive structures were built in locations around the world by kingdoms, revolutionaries, colonial forces, commercial entities, and more. Although most have outlived their military usefulness, dozens of these forts still survive, now renovated as museums, tourist attractions, hotels, or city parks.