Photographer Andy Hall joins the thousands of fans from west Africa who have gathered for Baaba Maal's annual Blues du Fleuve festival in Senegal. Here: Dancers wait to perform on stage. (Photo by Andy Hall/The Observer)

Revellers cool themselves in the Danube River during the Sziget music festival on an island in Budapest, Hungary August 12, 2015. The event is one of the biggest cultural events of Europe, offering art exhibitions, theatrical and circus performances and music concerts. Almost 200 performers from 47 countries will entertain the hundreds of thousands of visitors from 11 to 18 August. (Photo by Laszlo Balogh/Reuters)

A girl plays with colourful papers at the 23rd Sziget (Island) Festival on Shipyard Island in Budapest, Hungary, 13 August 2015. The festival is one of the biggest cultural events of Europe, offering art exhibitions, theatrical and circus performances and music concerts. Almost 200 performers from 47 countries will entertain the hundreds of thousands of visitors from 11 to 18 August. (Photo by Balazs Mohai/EPA)

Artists from Cirque Du Soleil: Totem perform at Royal Albert Hall on January 4, 2012 in London, England. (Photo by Danny Martindale/Getty Images)

A child plays with a soap bubble on the city hall plaza on March 14, 2015 in Paris. (Photo by Dominique Faget/AFP Photo)

It would seem to be something you'd see only in a cartoon or at a Phish concert, but according to park rangers in New South Wales, Australia, dozens of giant, fluorescent pink slugs have been popping up on a mountaintop there. The eight-inch creatures have been spotted only on Mount Kaputar, a 5,000-foot peak in the Nandewar Range in northern New South Wales. Scientists believe the eye-catching organisms are survivors from an era when Australia was home to rainforests. A series of volcanoes, millions of years of erosion and other geological changes “have carved a dramatic landscape at Mount Kaputar”, the park service wrote on its Facebook page, and unique arid conditions spared the slugs from extinction. (Photo by Michael Murphy/AFP Photo/NSW Environment Office)

A woman reacts after identifying a relative among the bodies of tsunami victims in Carita, Indonesia, Sunday, December 23, 2018. The tsunami occurred after the eruption of a volcano around Indonesia's Sunda Strait during a busy holiday weekend, sending water crashing ashore and sweeping away hotels, hundreds of houses and people attending a beach concert. (Photo by Fauzy Chaniago/AP Photo)

A model presents a creation at the Sophia Webster presentation during London Fashion Week in London, Britain February 20, 2017. (Photo by Neil Hall/Reuters)