“Not for the faint of heart”. Casa Milà, better known as La Pedrera, is a building designed by the Catalan architect Antoni Gaudí and built during the years 1905–1910, being considered officially completed in 1912. It is located at 92, Passeig de Gràcia in the Eixample district of Barcelona, Catalonia, Spain. (Photo by Stefano Scarselli)

Participants of the Sarenza High Heel Race 2015 warm up prior to the race during a party of the online shoe store, in Paris, Thursday, October 15, 2015. Competitors in teams of three girls race wearing shoes with more than 8 cm-high heels. (Photo by Francois Mori/AP Photo)

Eugloss dilemma, male, Florida, Biscayne National Monument. (Photo and caption by Sam Droege/USGS Bee Inventory and Monitoring Lab)

A competitor loses his shoe during the annual race on high heels during Gay Pride celebrations in the quarter of Chueca in Madrid, Spain, June 30, 2016. (Photo by Susana Vera/Reuters)

Iguazu Falls are waterfalls of the Iguazu River on the border of the Brazilian state of Paraná and the Argentinian province of Misiones. The falls divide the river into the upper and lower Iguazu. The Iguazu River rises near the city of Curitiba. It flows through Brazil for most of its course. Below its confluence with the San Antonio River, the Iguazu River forms the boundary between Argentina and Brazil.

In this March 14, 2015 photo, tourists take pictures from a viewing area at Iguazu Falls in Brazil. From walkways and bridges, viewers can count 270 water falls almost 100 meters (330 feet) high. (Photo by Jorge Saenz/AP Photo)

Victoria Falls is a town in the province of Matabeleland North, Zimbabwe. It lies on the southern bank of the Zambezi River at the western end of the Victoria Falls themselves. It is connected by road and railway to Hwange (109 km away) and Bulawayo (440 km away), both to the south-east.

Mitchell Falls are a chain of four waterfalls located in the remote north of the Kimberley Region (Western Australia, a little more than 2,000 kilometers northeast of Perth.). It is a part of Mitchell River National Park (one of the protected areas of Western Australia), Mitchell Falls are probably one of the park’s main attractions.