A passenger takes off his pants as others not wearing pants dance while waiting for a subway train during the “No Pants Subway Ride” in Mexico City, Mexico, February 21, 2016. The event is an annual flash mob and occurs in different cities around the world, according to its organisers. (Photo by Carlos Jasso/Reuters)

The launch of a rocket into space is projected on Dubai's Burj Khalifa on February 9, 2021 as the UAE's “Al-Amal” – Arabic for “Hope” – probe's to Mars carries out a tricky manoeuvre to enter the Red Planet's orbit. A tense half-hour today will determine the fate of “Hope”. If successful, the probe which is designed to reveal the secrets of Martian weather, will become the first of three spacecraft to arrive at the Red Planet this month. (Photo by Giuseppe Cacace/AFP Photo)

Beautiful red sunset sky over Edinburgh, Scotland. Edinburgh is the capital city of Scotland and a popular tourist destination. It is also a major European financial (fund management) centre. Prominent buildings from left to right are: Edinburgh Castle, The Balmoral Hotel Clock Tower and The Scott Monument. (Photo by John Lawson/Getty Images)

People take photos with the skyline of the central business district in Singapore on September 10, 2015. (Photo by Edgar Su/Reuters)

A brig with scarlet sails travels on the Finnish Gulf coast during a rehearsal for the the Scarlet Sails festivities marking school graduation in St. Petersburg, Russia, early Saturday, June 27, 2020. This year the festival will not be held in the city center, but on the Finnish Gulf. Due to the coronavirus pandemic, there will be no spectators but the event will be broadcast on television. (Photo by Dmitri Lovetsky/AP Photo)

A full moon is seen behind buildings at night in Ashkelon, southern Israel on December 1, 2020. (Photo by Amir Cohen/Reuters)

Participants wearing costumes walk along a main street during a Halloween Parade in Marikina city, east of Manila, Philippines, on October 30, 2014. (Photo by Romeo Ranoco/Reuters)

Chefchaouen or Chaouen is a city in northwest Morocco. It is the chief town of the province of the same name, and is noted for its buildings in shades of blue.