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)

Measuring just five feet at its widest point, the ultra-thin home was unveiled in the Polish capital of Warsaw on Sunday, October 21, 2012. Photo: The Keret House is squeezed into the space between two apartment buildings in Warsaw. There's a four-inch gap between the apartment buildings to either side. A perforated steel facade was used to allow in more light. (Photo by Andrea Meichsner/The New York Times)

A picture rotated 180 degrees shows visitors walking inside an “Upside-down House” attraction at the VVTs the All-Russia Exhibition Center in Moscow, on January 14, 2014. The attraction to experience a new perspective of a house standing upside down was opened first time in Russia, the show organisers said. (Photo by Alexander Nemenov/AFP Photo)

The Vietnam Slide Project was created by photo editor Kendra Rennick, who began collecting photo slides after a close friend lost her father, a Vietnam veteran. Her friend found a box of slides that her father had taken while in Vietnam and from there Rennick has continued to collect photographs that Vietnam veterans took during their tours of duty. Here: A photo taken from the collection of D.Thornton, who served in the First Air Cavalry division of the United States Army. (Photo by D.Thornton/The Vietnam Slide Project)

A wedding couple poses for a photographer during a wedding photo shoot March 9, 2011 in Hanoi, Vietnam. Its is traditional for middle and upper class Vietnamese couples do a wedding fashion shoot posing for wedding portraits a few weeks before the wedding so that a wedding photo book is produced. (Photo by Paula Bronstein /Getty Images)

Villagers gather long grass in the Mekong Delta, Vietnam in the first decade of February 2024. The grasses are used as an alternative for plastic products such as baskets. (Photo by Natnattcha Chaturapitamorn/Solent News)

A woman poses for a photo next to lotus flowers in West lake in Hanoi, Vietnam, 09 June 2025.. Lotus flowers bloom from late May to August in Vietnam and are commonly found growing in the muddy waters of lakes and ponds across the country. (Photo by Luong Thai Linh/EPA)

A woman drives a scooter with her dog in Hanoi on December 10, 2021, as Vietnamese officials in the central city of Hoi An announced it was set to be the country's first dog and cat meat free city. (Photo by Nhac Nguyen/AFP Photo)