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 150-square-metre Villa Ypsilon was designed by London- and Brussels-based firm LASSA, which is headed up by architects Theo Sarantoglou Lalis and Dora Sweijd.

Visitors visit the upside-down family size house in Taipei, Taiwan, 23 February 2016. The three story upside-down family size house attracts hundreds of visitor’s who are amused with the exhibit. According to the organizers, the total cost of the construction is around 600,000 US Dollars and took 2 months to complete. (Photo by Ritchie B. Tongo/EPA)

Australian World War Two veterans place crosses and flags at graves before attending the French-British ceremony at the British War cemetery in Bayeux, June 6, 2014. REUTERS/Leon Neal/Pool

A cook grills chicken during the Festival des Grillades, in the yard of the Culture Palace of Abidjan, September 5, 2015. The two day festival was iniated in 2008 to promote Ivorian cuisine, which revolves around grilled food. (Photo by Luc Gnago/Reuters)