Chicago's 81-storey Aqua skyscraper has won the US Skyscraper of the Year award for last year.
The jury awarded the building the Emporis Skyscraper Award for its unique shape and construction as well as its green design innovations.
The tower was designed by architect Jeanne Gang of Studio Gang Architects and delivered by James McHugh Construction for developer Magellan Development Group. Magnusson Klemencic Associates served as Aqua's structural engineer.
Based on a nautical theme, Aqua features a wavy façade with undulating balconies and flat glassy planes. Each balcony's perimeter varies slightly from the others.
The tower also features light coatings on concrete to avoid a heat island effect and a vegetated roof at podium level.
Aqua is currently the third-tallest building in the world and has applied for LEED certification.
It beat 305 entries to win the award. O14 in Dubai came second and The Met in Bangkok took the third place.