Museum employee Victoria views a giant grouper fish specimen at the Natural History Museum in west London March 25, 2015. It forms part of a new exhibition, “Coral Reefs: Secret Cities of the Sea”, featuring a panoramic virtual dive and over 250 specimens from the Museum's coral, fish and marine invertebrate collection, which opens on March 27. (Photo by Toby Melville/Reuters)

Commuters by with the buildings of the banking district in background in Frankfurt, Germany, Thursday, February 6, 2020. (Photo by Michael Probst/AP Photo)

A fado singer smokes a cigarrette outside a fado house at the Alfama neighborhood in Lisbon on May 8, 2019. From fado sounds to Cape Verde mornas or bossa nova: the Lisbon nights, where musicians from all over the world meet, have largely inspired Madonna's new album, who has been in the Portuguese capital since 2017. (Photo by Patrícia de Melo Moreira/AFP Photo)

Men and Women dressed as zombies walk through Hyde Park on February 25, 2012 in Sydney, Australia. The annual Zombie Walk raises money for the Brain Foundation and this year teamed up with FX channel in promotion of “The Walking Dead” series premiering in Australia this weekend. (Photo by Brendon Thorne/Getty Images)

Dargavs is a small necropolis outside the village of Dargavs in North Ossetia-Alania. It comprises 99 different tombs and crypts. It is often called city of the dead. Some sources say the oldest of the crypts dates back to the 12th century, though others say the oldest crypt dates back to 14th century and some say it dates to the 16th century. At the back of the complex there is a tower, though the top of it is destroyed.

People watch participants, whose faces are painted as popular Mexican figure “Catrina”, during the annual Catrina Fest, part of Day of the Dead celebrations, in Mexico City, Mexico, November 2, 2016. (Photo by Edgard Garrido/Reuters)

In this aerial view the officers' building and an auditorium stand at the former Soviet military base on January 26, 2017 in Wuensdorf, Germany. Wuensdorf, once called “The Forbidden City”, was the biggest base for the Soviet armed forces in communist East Germany from 1945 until the last Soviet troops left in the early 1990s following the end of the Cold War and the reunification of Germany. (Photo by Sean Gallup/Getty Images)

A dog catches a wave during the Surf City Surf Dog Contest in Huntington Beach, California September 27, 2015. (Photo by Lucy Nicholson/Reuters)