People cool off at the water park during the “Circuit” the international gay festival in Vilassar de Dalt, Spain, Tuesday, August 9, 2016. The special international event has attracted many thousands and the gay festival “Circuit” runs until August 14. (Photo by Manu Fernandez/AP Photo)

Revellers celebrate “Ash Monday” by participating in a colourful “flour war”, a traditional festivity marking the end of the carnival season and the start of the 40-day Lent period until the Orthodox Easter,in the port town of Galaxidi, Greece, February 27, 2017. (Photo by Alkis Konstantinidis/Reuters)

Vietnam’s Son Doong cave, the largest in the world, could hold a 40-story skyscraper inside. The pristine ecosystem has its own river and jungle. Despite its size, Son Doong wasn’t discovered until 1991. It was lost again for nearly two decades and was fully explored for the first time in 2009. (Photo by Jason Speth/HuffPost)

A guest dressed as a zombie attends the Middle East Film & Comic Con (MEFCC) in Gulf emirate of Dubai, United Arab Emirates, 11 April 2019. The event runs until 13 April 2019. (Photo by Ali Haider/EPA/EFE)

Lukas Irmler balances on a 800 meter long highline 200 meters above Segnesboden, on Friday, June 28, 2019, in Flims, Switzerland. The highline is Switzerland's longest and will be set up untill Sunday in the Sardona World Heritage Region. (Photo by Gian Ehrenzeller/Keystone via AP Photo)

Participants of the the goth festival “Wave Gothic Festival” walk in fancy costumes along the festival area in Leipzig, central Germany, Saturday, May 23, 2015. About 20,000 members of the scene are expected to attend one of the world's largest gothic and “dark” culture festivals until May 25, 2015. (Photo by Jens Meyer/AP Photo)

SoftBank's human-like robot named “Pepper” poses for pictures in its role as a PR manager of Tottori prefecture at the prefecture speciality store in Tokyo, Japan, July 1, 2015. Pepper will work at the store until July 2, as the first workplace venue for its temporary staffing service. (Photo by Yuya Shino/Reuters)

Actors and dancers perform during the press rehearsal for the “ARISE Grand Show” at the Friedrichstadt-Palast theater in Berlin, Germany, 15 September 2021. Premiere of the show is scheduled for 16 September and will amaze vistors with “extravagant costumes, breathtaking stage sets and artistic excellence” until February 2022 as the theater promises on its website. (Photo by Filip Singer/EPA/EFE)