Urban photographer Roman Robroek spent five years scouring the continent for the grandest examples of forgotten architectural beauty. Here: Watch your step on this Polish spiral staircase. (Photo by Roman Robroek/South West News Service)

The Sculpture Bank (2017) by Chinese artist Mu Boyan is exhibited along the Bondi to Tamarama Coastal walk as part of the Sculpture by the Sea exhibition in Sydney, Australia, October 18, 2018. (Photo by Charlotte Curd/The Guardian)

Germany, Business couple making love under desk. (Photo by Roman Maerzinger/Getty Images)

The sun rises between Sgurr nan Gillean and Knight’s Peak, Black Cuillin, Isle of Skye. (Photo by Adrian Trendall/Mountain Photo of the Year)

A stay-at-home mom's surreal iPhone snaps of her children have seen her rack up more than a half-million Instagram fans. Ali Jardine, 42, photographs silhouettes of her two kids in fairy-tale environments, from a spiraling night sky to sunsets. The creative mom has gained more than 519,000 followers online since she got her first iPhone in November 2010. And due to her success, Ali, who is from Petaluma, Calif., has been able to monetize her work, helping the likes of HP and Samsung with Instagram campaigns. Here: a girl on a swing in the sky. (Photo by Ali Jardine/Caters News)

Competitors line up their boats for some formalities during the Aberdeen Dragon Boat Races. (Photo by Jessica Hromas)

Three-month old cheetah cubs make their public debut at the Smithsonian National Zoo on July 24, 2012 in Washington, DC. (Photo by T.J. Kirkpatrick)

Lebanese students dance during “The Big Dance” event in downtown Beirut, near the parliament May 9, 2015. About 1000 students from all over Lebanon gather and take part in a joint dance with the aim of encouraging people to get into dance and increase fitness levels. This initiative is part of the British Council's project, Connecting Classrooms which aims at building links between schools in the UK and Lebanon. (Photo by Aziz Taher/Reuters)