Ancient Egyptian pyramids and modern pyramid-shaped structures are awesome, but what could be better than walking into an upside-down pyramid?

The Katimavik (means "Gathering Place" in Inuit) of the Canadian Pavilion at Expo 67 in Montreal, Canada, designed by Rod Robbie, opened in 1967

(via Musée québécois de Culture populaire, Encyclopedia of French Cultural Heritage in North America and Expo 67)

The Geisel Library building of the University of California, La Jolla, San Diego, California, designed by William L. Pereira & Associates, completed in 1970

(via The UC San Diego Library)

Tempe City Hall, Tempe, Arizona, completed in 1971, designed by Michael & Kemper Goodwin.

(via Franz Koeck and Tempe Preservation)

St. Petersburg Pier, St. Petersburg, Florida, designed by William B. Harvard Sr., constructed in 1973, closed in May 2013. It had an aquarium, restaurants, bars, specialty shops and galleries.

(via Matthew Paulson and John McNicholas)

State Government Offices in Geelong, Victoria, Australia, constructed in 1978 and 1979

(via Ben Nguyen)

The minimalist Hong Kong Coliseum (also known as Hung Hom Coliseum), Kowloon, Hong Kong, completed in 1981

(via Wikimedia Commons)

Slovak Radio Building, Bratislava, Slovakia, designed by Štefan Svetko, Štefan Ďurkovič and Barnabáš Kissling, completed in 1983. The 271 ft (82.64 m) high building has a concert hall and used for regular broadcasting since March 1985.

(via Miroslav Petrasko and Mark Turner)

The Ministry of Interior, Riyadh, Saudi Arabia, opened in 1990

(via Wikimedia Commons and Ministry of Hajj)

The glass and titanium-panelled Conference Tower of Tokyo Big Sight (Tokyo International Exhibition Center), Ariake, Tokyo Bay, Japan, opened in 1996.

(via Morio, Nemo's great uncle)

The Pyramid on Central, an office building in Phoenix, Arizona, designed by Tomasso Engineering

(via Erica Chang and Chris English)

Hanoi Museum, Hanoi, Vietnam, designed by GMP, constructed between 2007 and 2010

(via GMP)

China Pavilion at Expo 2010 (also known as the Oriental Crown), Shanghai, China, designed by He Jingtang. After the Expo it was converted to a museum, and it was reopened as the China Art Museum two years ago.

(via Wikimedia Commons and Kwong Yee Chong)