National Park Service's earlier, more traditional buildings, and was built as part of its "Mission 66" modernization and expansion program. As the first major building of that effort, it was a high-profile success, bringing critical notice for its Modern design and launching the careers of its designers. It was designated a National Historic Landmark in 1975 for its architecture and its importance to the Park Service's program. Kill Devil Hill and the Memorial Tower A granite monument, dedicated in 1932, is perched atop Kill Devil Hill, commemorating the achievement of the Wright brothers. They conducted many of their glider tests on the massive shifting dune that was later stabilized to form Kill Devil Hill. Inscribed in capital letters along the base of the memorial tower is the phrase "In commemoration of the conquest of the air by the brothers Wilbur and Orville Wright conceived by genius achieved by dauntless resolution and unconquerable faith." Atop the tower is a marine beacon, similar to one found in a lighthouse. The doors of the tower are stainless steel over nickel, with a price of $3,000 in 1928 (). The six relief panels represent the conquest of the air: Left Door (top to bottom): The contraptions of the French locksmith Besnier, who thought he could fly if he propelled himself into the air while wearing paddles on his arms and legs; An homage to Otto Lilienthal, a German who died while conducting gliding experiments; A reference to a French philosopher who thought that since dew rose in the morning, if it could be placed in an expandable bag attached to a box and sail, it would naturally rise when placed in the sun. (It didn't.) Right Door (top to bottom): Icarus, the Greek mythological figure who tried to fly from Crete by attaching feathers to his arms with wax. He fell when he flew too close to the sun, melting the wax; Bird flight to plane flight, or the rise of a phoenix; Kites used by the Wrights and others in early experiments Building the Memorial The tower was designed by Rodgers and Poor, a New York City architectural firm; the design was officially selected on February 14, 1930. Prior to the memorial's construction, the War Department selected Captain William H. Kindervater of the Quartermaster Corps to prepare the site for construction and to manage the area landscaping. To secure the sandy foundation, Captain