If there is one requirement of architecture, it's that the structure must remain upright. Forget any aesthetic purpose, architects would be out of a job if their buildings continually failed to meet this one test. Yet some architects push the boundaries, seemingly daring with Newton's universal law of gravity, to design buildings that not only appear to defy logic, but are beautiful at that. From a cantilevered barn designed by the Dutch-based firm MVRD to an impressively stacked building in Hanover, Germany, by the Stuttgart-based firm Behnisch Architekten, these 12 buildings seem impossible to conceive, let alone build. Of course, all of these structures passed strict zoning laws before they were erected. What is not guaranteed, however, is whether merely looking at them will cause you vertigo.

Building: Museum of Tomorrow Location: Rio de Janeiro, Brazil Architect: Santiago Calatrava Fun fact: Completed in 2015, 1.4 million people visited the Museum of Tomorrow during its inaugural year, far exceeding the anticipated 450,000 visits. It is currently the most-visited museum in Brazil.

Building: Takasugi-an (Tea house on the Tree) Location: Chino, Nagano Prefecture, Japan Architect: Terunobu Fujimori Fun fact: The name Takasugi-an means, “a tea house [built] too high.”

Building: MARTa Herford Location: Herford, Germany Architect: Frank Gehry, Hartwig Rullkötter Fun fact: The art museum has a statue of Tupac Shakur at the entrance

Building: Dancing House Location: Prague, Czech Republic Architect: Frank Gehry Fun fact: The inspiration for the structure originally came from the famous dancers Fred Astaire and Ginger Rogers.

Building: NORD/LB Bank Location: Hanover, Germany Architecture firm: Behnisch, Behnisch & Partner Fun fact: The bank has invested in an extensive art collection, including some 3,000 works by such postwar artists as Georg Baselitz, Gerhard Richter, Sol LeWitt, Jeff Koons, and Jannis Kounellis, among others. The works are displayed within the several company buildings.

Building: Ragnarock Location: Roskilde, Denmark Architecture firms: MVRDV and COBE Fun fact: The city of Roskilde is filled with old cement factories, which makes the design for Ragnarock, a museum dedicated to rock music, all the more exciting.

Building: Odeillo Solar Furnace Location: Font-Romeu-Odeillo-Via, France Fun fact: The Odeillo solar furnace is the world's largest solar furnace. The location was selected because of the duration (more than 2,500 hours per year) and the quality of sunlight that hits the area.

Building: Cube Houses Location: Rotterdam, Holland Architect: Piet Blom Fun fact: The design for the 38 homes was meant to represent a village within a city, but practically speaking, the design was intended to optimize the space inside of the home set in an urban space.

Building: One Central Park Location: Sydney Architect: Jean Nouvel Fun fact: With a mix of various plants and flowers on the structure's exterior reaching nearly 165 feet high, the building's vertical hanging garden is the tallest in the world.

Building: Heydar Aliyev Center Location: Baku, Azerbaijan Architect: Zaha Hadid Fun fact: The significance of the structure's swooping design is all the more important, as it's a distinct departure from the rigid Soviet-era architecture that once defined the region.

Building: Balancing Barn Location: Thorington, England Architecture firm: MVRDV Fun fact: One one end of the home, visitors inside the space can experience nature at ground level. On the other end, however, they are able to view the world as if they were at tree height, a phenomenon that occurs without the visitor having to climb a set of stairs.

Building: Learning Hub at the Nanyang Technological University Location: Singapore Architecture firm: Heatherwick Studio Fun fact: The design was meant to rethink the ways in which academic buildings are built, allowing students and professors to more easily interact in an open environment.