Cupolas on barns, houses, and garages can now be useful, ornamental, or both. Experienced cupola builders understand that achieving functionality requirements is as vital as selecting the proper design. Many farmers, garage owners, and house dwellers choose to add a cupola as an economical way to protect themselves from the elements. A well-built cupola will provide adequate shelter for a person or family during severe weather. The earliest reference to a cupola used for shelter was in 1556, but they were not in widespread use until much later. The invention of the iron roof truss made it possible to build large cupolas. In fact, the Baltimore Sunlight Cupola, built in 1872, is still in use today. It has been designated as a National Historic Landmark. People started building cupolas to protect themselves from the sun, rain, snow, wind, heat, and cold. They also used them for decoration. Some famous people who lived in cupolas include George Washington, Thomas Jefferson, and Abraham Lincoln. Today, many farmers, garage owners, and house dwellers continue to use cupolas to protect themselves from the elements. Cupolas are very efficient at keeping out heat and rain. This is because all they need is a solid shell with a few small openings for air to flow through.