A performer takes part in a street parade as part of the opening ceremony of the Ibero-American Theater Festival in Bogota, Colombia, March 12, 2016. (Photo by John Vizcaino/Reuters)

People walk on a sightseeing platform in Zhangjiajie, Hunan Province, China, August 1, 2016. China has opened a 100-metre-long glass skywalk stretching around a cliff on the side of the Tianmen Mountain. The skywalk provides a view of a 300-metre drop and overlooks Tongtian Avenue, a mountain road with 99 turns that snakes up the mountain. When translated in English, it means “Avenue to the Sky”. (Photo by Reuters/Stringer)

Marco Fiera from NoFit State Circus tries out the SkyWire, the new zip wire attraction which opens to the public this week at The Eden Project on July 17, 2012 in St Austell, England. The new 740m zip wire, currently the longest in England, allows the public a bird's eye view of the iconic Rainforest and Mediterranean Biome structures as well as the Cornish attractions outdoor gardens. The Eden Project – which opened in 2001 and has attracted over one million visitors – showcases 100,000 plants from around the world in two giant transparent domes, one of which is the world's largest greenhouse, each recreating different climate conditions. (Photo by Matt Cardy)

General view of the entrance to the Swarowski Crystal World museum on its reopening day following renovation, in the western Austrian village of Wattens April 30, 2015. (Photo by Dominic Ebenbichler/Reuters)

Alessandra Ambrosio arrives for the screening of “The Dead Don't Die” and the Opening Ceremony of the 72nd annual Cannes Film Festival in Cannes, France, 14 May 2019. Presented in competition, the movie opens the festival which runs from 14 to 25 May. (Photo by Ian Langsdon/EPA/EFE)

Labourers stack dried bricks inside a kiln, where they will be fired, at a brick factory on the outskirt of Sanaa, Yemen, June 1, 2016. Traditional mud brick tower houses have always been a source of pride to Yemenis, and over a year into a devastating civil war, they are also providing some much-needed jobs in the ancient capital Sanaa. (Photo by Mohamed al-Sayaghi/Reuters)

A man wearing a Guy Fawkes mask enjoys a ride on a 350-meter (1148 feet) long water slide during 2015 City Silde Festa in central Seoul, South Korea, July 19, 2015. A 350 meter-long waterslide has been installed in downtown of Seoul, the longest waterslide to be recorded in Korea, according to local media. (Photo by Kim Hong-Ji/Reuters)

The Verzasca is a Swiss 30-km long mountain river originating at Pizzo Barone and flowing into Lake Maggiore. It is known for its clear turquoise water and vibrant colored rocks, as well as its treacherous currents. The Verzasca Dam is a few kilometers upriver from this lake.