Completion is near on Monaco's tallest skyscraper ever, and its first new one since the 1980s. Fueled by a luxury-housing boom in the tax-haven nation, the Odeon Tower's so-called Sky Penthouse is expected to sell for more than any other apartment in the world has ever sold before. Photo: The five-story Sky Penthouse is expected to be complete in September 2015. The water slide extends from a dance floor in the residence down to a private infinity pool. (Photo by Tour Odeon)

Two robotic legged squad support system (LS3) machines by the Defense Advanced Research Project Agency follow a technician during a demonstration at Joint Base Myer-Henderson Hall, Virginia, on September 10, 2012. (U.S. Marine Corps photo by Sgt. Mallory S. VanderSchans via The Atlantic)

Two Bunny Girls from the Playboy Club and two Penthouse Pets from the Penthouse Club prepare to take part in the annual Good Friday waiters and waitresses race in Battersea Festival Gardens, London, 28th March 1972. (Photo by Ian Showell/Keystone/Hulton Archive/Getty Images)

A signing session during the International tattoo convention at Tobacco Dock in east London, England on September 27, 2019. (Photo by Steve Parkins/Rex Features/Shutterstock)

Aerial view of Skanderbeg Square in Tirana, lit with Christmas decorations and surrounded by an open Christmas market on December 29, 2021. (Photo by Gent Shkullaku/AFP Photo)

Performers walk past a light installation “Butterfly Effect” designed by Japan artist Masamichi Shimada, at the Battersea Power Station in London, Thursday, January 25, 2024. The Light Festival involved seven light installations from British and international artists at Battersea Power Station, which illuminated the winter evenings between Jan. 25 and Feb, 25. (Photo by Kin Cheung/AP Photo)

A migrant carries his belongings as he arrives at the Beijing railway station to catch a train in Beijing, Friday, February 13, 2015. (Photo by Andy Wong/AP Photo)

Alluvial Fan, China. A vast alluvial fan blossoms across the desolate landscape between the Kunlun and Altun mountain ranges that form the southern border of the Taklimakan Desert in China’s XinJiang Province. Image taken by the ASTER instrument on NASA’s Terra satellite on May 2nd, 2002. (Photo by NASA/GSFC/USGS EROS Data Center)