Funchal Airport in Madeira Island (Portugal) extended its runway back in 2003… over the ocean shore. The extension is now supported by 180 concrete pillars, each about 70 meter (almost 230 feet high). Previously the runway was about 1400 meters (4593 feet – not enough for an international airport) in a area surrounded by mountains and the ocean, making the runway very dangerous for landing. Funchal Airport was the scene of the most devastating airline accident in history (read here for more info).
The new runway won the Outstanding Structures Award and is now considered the “Oscar” of engineering structures.