The bridge is 408 meters long and weighed approximately 1,500 metric tons when built. Originally supported by four columns, two more were added in later years to support the weight of heavier rail cars.
Sculptor Frederic-Auguste Bartholdi is credited with bringing the concept of the Statue of Liberty to fruition, deriving inspiration from the 19th-century penchance for grandiose monuments. He originally designed the statue for placement at the Suez Canal, but the project was never commissioned. After a promotional trip across America, Bartholdi's ideas finally took hold in 1874, and a Franco-American coalition was formed to fund the project, with the Americans building the base and the French the statue.
Built to cross one of the steepest valleys along the Douro River, the Ponte Maria Pia was the first major work to emerge from the French firm of Gustav Eiffel and Company, establishing Eiffel as an important bridge designer and civil engineer of his day. Resting on a parabolic arch spanning 160 meters, the Ponte Maria Pia was the longest iron arch bridge in the world at the time of its construction. The bridge's latticework construction reflects the later design of the well-known Eiffel Tower, erected in Paris to commemorate the International Exposition of 1900.
The Eiffel Tower was built for the International Exhibition of Paris of 1889 commemorating the centenary of the French Revolution. Of the 700 proposals submitted in a design competition, Gustave Eiffel's was unanimously chosen. At 300 meters and 7,000 tons, it was the world's tallest building until 1930.
The elevators ascend and descend within the curved legs of the tower, starting at an angle of 54 degrees from horizontal at the base and leveling out to 78 degrees at the top. The elevator cars are built with seatbacks that rotate to adjust to the varying angle.