Iron structures are buildings or frameworks made primarily from iron, a strong and durable metal. These structures are often used in construction due to their ability to support heavy loads and withstand various environmental conditions. Common examples include bridges, skyscrapers, and industrial buildings. The use of iron in construction dates back to the 19th century, when advancements in metallurgy allowed for the mass production of iron materials. This innovation led to the development of iconic structures like the Eiffel Tower and the Brooklyn Bridge, showcasing the versatility and strength of iron in modern engineering.