BERLIN, GERMANY - NOVEMBER 11: Sculptor Oleg Bessonov creates a rosette from clay at the Schlossbauhuette studio where a team of sculptors is creating decorative elements for the facade of the Berliner Schloss city palace on November 11, 2011 in Berlin, Germany. The Berliner Schloss was the residence of the Prussian Kaiser and was among the major architectural landmarks of Berlin until it was heavily damaged by Allied bombing in 1945. The communist authorities of East Berlin demolished the building in the 1950s, and today's Berlin government is pursuing an ambitious project to rebuild the palace according to a design by Italian architect Franco Stella, which will recreate the facade of the building but with a modern interior at a cost of approximately EUR 590 million. The Humboldt Forum, the foundation leading the project, has given the Schlossbauhuette sculptors the formidable task of recreating the hundreds of architectural elements that decorated the facade, and though some original pieces were saved, more often the sculptors have only old black and white photos as reference. (Photo by Sean Gallup/Getty Images)

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)

This computer image provided Monday March 17, 2014 by the Press Office of socialist candidate to Paris Mayor Anne Hidalgo, shows a tunnel of abandoned railway from the 19th century, now ramshackle and overgrown, turned into a cinema. Hidalgo’s plan envisions not just a green space but in the tunnels, places for farming fish and mushrooms. (Photo by AP Photo/Anne Hidalgo's Press Office)

A visitor looks at a creation at the Artemide space during Milan Design Week, April 14, 2015. The Milan Design Week will be held until April 19. (Photo by Stefano Rellandini/Reuters)

A concept illustration of the world's first forest in the sky, the Bosco Verticale green twin towers currently under construction in Milan, Italy. Towering over the city skyline the world's first forest in the sky will be a sight to behold. With tree equal to one hectare of forest spanning 27 floors these 365 and 260 foot emerald twin towers will be home to an astonishing 730 trees, 5,000 shrubs and 11,000 ground cover plants. (Photo by Boeri Studio)

In this September 1, 2015 photo, street artists Jenaro de Rosenzweig, left, and Alejandro Revilla pose for a portrait behind a restaurant's window covered with a mural by artist Francisco Munoz, signed with his artist's name below, in the Roma Norte neighborhood of Mexico City. Rosenzweig and Revilla founded the “Street Art Chilango” cooperative in March 2013, which is filling neighborhoods with public art by local street artists. (Photo by Rebecca Blackwell/AP Photo)

Construction work on the tower began in November 2008. Upon its completion this year the building will stand approximately 632 meters (2,073 ft.) high and will have 121 stories. It is expected to open to the public in 2015. (Photo by Rex Features)