A baby hippo swims under the water in its enclosure at Prague Zoo, Czech Republic, February 24, 2016. The baby was born on January 28, and is yet to be named. (Photo by David W. Cerny/Reuters)

A child looks at a polar bear swimming under a water in its enclosure on a hot summer day at Prague Zoo, Czech Republic, July 30, 2015. (Photo by David W. Cerny/Reuters)

A rabbit fails to clear an obstacle during a bunny hop competition at the Old Town Square in Prague, Czech Republic, Monday, April 14, 2014. (Photo by Petr David Josek/AP Photo)

Soviet Army soldiers sit on their tanks in front of the Czechoslovak Radio station building in central Prague during the first day of Soviet-led invasion to then Czechoslovakia on August 21, 1968. (Photo by Libor Hajsky/Reuters)

Ammunition airlift into besieged Khe Sanh, Operation Pegasus, April 1968. (Photo by Larry Burrows/AP Photo)

A participant dressed up in a costume attends the 2021 Prague Comic Con in Prague, Czech Republic, October 16, 2021. (Photo by David W. Cerny/Reuters)

Participants in fancy costumes take part in march during the Prague Pride parade in downtown Prague, Czech Republic, 10 August 2019. Several thousands of people attended the 9th Prague Pride to support the LGBT (lesbian, gay, bisexual and transgender) communities. (Photo by Martin Divisek/EPA/EFE/Rex Features/Shutterstock)

Hooded demonstrators vandalise a shop window in Mexico City, during the commemoration of the 50th anniversary of the 1968 Tlatelolco student massacre, on October 2, 2018. Fifty years ago, Mexican troops opened fire on student demonstrators, killing hundreds just days before Mexico City hosted the 1968 Olympics – one of the darkest episodes in a year of global turbulence. (Photo by Ronaldo Schemidt/AFP Photo)