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 attend the 25th edition of the Sziget Festival on August 9, 2017 in Budapest, Hungary. The Sziget Festival, one of the largest music and cultural festivals in Europe, celebrates its 25th anniversary in 2017, taking place from August 9-16 on the Hajogyari Sziget in Budapest. (Photo by Laszlo Mudra/Rockstar Photographers)

A group of scantily-clad women pose for photographs at the annual Venus erotic trade fair in Berlin, Germany on 12 October 2017. Venus Berlin is among the largest international erotic trade fairs, with more then 250 exhibitions from 40 countries and 30,000 visitors. (Photo by Alamy Live News)

Participants wearing fantasy costumes attend the 4th Hero Festival in Marseille, France on November 11, 2017. The 4th Hero Festival edition has attracted all sorts of people to role play their favourite characters from all kinds of movies and comic book legends. (Photo by Jean-Paul Pelissier/Reuters)

South Korea's Black Eagles aerobatics team perform a maneuver during a preview of the Singapore Airshow at Changi exhibition center in Singapore February 14, 2016. The Airshow will take place from February 16-21. (Photo by Edgar Su/Reuters)

View of a raccoon dog or Tanuki (Nyctereutes procyonoides) at the Chapultpec Zoo in Mexico City on August 06, 2015. This species is native from Japan and China. (Photo by Alfredo Estrella/AFP Photo)

Crowds wave as HMS Daring, the largest and most powerful destroyer warship ever built for the Royal Navy, leaves Portsmouth Harbour on January 11, 2012 in Portsmouth, England. HMS Daring, the first of six new Type 45 destroyers embarked from Portsmouth on its maiden deployment, a seven-month mission to the Middle East. (Photo by Matt Cardy/Getty Images)

Sister Milly Wu (16) and Chloe Wu (18), both students from Manchester pose for photographs at the Hyper Japan 2012 Event at the Earls Court Exhibition Centre on February 24, 2012 in London, England. (Photo by Matthew Lloyd/Getty Images)