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 Ukrainian woman begs Ukrainian President Petro Poroshenko to stop the bombing in Donetsk after shell hit the residential area where she lives, killing two civilians in Donetsk's Kyibishevsky district, on January 29, 2015. (Photo by Manu Brabo/AFP Photo)

Bonbibi, Treehouse Point, Fall City, WA. The Bonbibi is balanced on two steel yokes. The yokes spread out the load and allow for tree growth and movement in the wind. A small deck hangs from the beams below and uses the treehouse itself to shelter guests. (Photo by Pete Nelson)

A Hindu holy man on his way to the annual holy dip at Gangasagar, gestures towards a visitor as he rests at a transit camp in Kolkata, India, Wednesday, January 6, 2016. Thousands of Hindu pilgrims are expected to take the annual holy dip at Gangasagar, where the Ganges River reaches the Bay of Bengal, on the auspicious Makar Sankranti festival day that falls on Jan.14. (Photo by Bikas Das/AP Photo)

In this November 7, 2016 photo, “El Menor”, a member of “Los Cainos” self-defense group formed by the Marval fishing family, holds a homemade gun before starting a night patrol to help protect fishermen from pirate attacks in Punta de Araya, Sucre state, Venezuela. Pirates are terrorizing the coastal state of Sucre, once home to the world's fourth-largest tuna fleet and a thriving fishing industry. (Photo by Rodrigo Abd/AP Photo)

Star Wars fan Mike Deguzman practices with a toy lightsaber after purchasing some new toys that went on sale at midnight in advance of the film “Star Wars: The Force Awakens” in Times Square in the Manhattan borough of New York, September 4, 2015. (Photo by Carlo Allegri/Reuters)

A meteorite burns up in the atmosphere as seen in this photo taken near of Salgotarjan, 109 kms northeast of Budapest, Hungary, late 21 April 2015. The Moon and Venus can be seen on the left. (Photo by Peter Komka/EPA)

Tourists wear protective masks in Sanur, Bali, Indonesia, 15 March 2020. Indonesia has around 80 active cases of Covid-19. More than 70,000 people worldwide have recovered from coronavirus, nearly half of the total infections recorded since the outbreak began. (Photo by Made Nagi/EPA/EFE)