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 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)

Handout photo issued by Easyart of an experimental motorcycle as an archive of weird and wacky innovations has been unearthed by an amateur historian as he trawled through a collection of images spanning the last 100 years. (Photo by Easyart/PA Wire)

Aleksandra Krunic, of Serbia, drops to the court after defeating Petra Kvitova, of the Czech Republic, during the third round of the 2014 U.S. Open tennis tournament, Saturday, August 30, 2014, in New York. (Photo by Kathy Willens/AP Photo)

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)

Participants wearing historical attire compete on historical high wheel Penny Farthing bicycles in the traditional 'One Mile Race' at Letna Park in Prague, Czech Republic, November 7, 2015. The meeting of Penny Farthing bicycles is taking place for the 22th time. (Photo by Filip Singer/EPA)

Participant wearing medieval costumes perform during an annual re-enactment of a battle near the village of Libusin, Czech Republic, April 23, 2016. About 2000 enthusiasts have come to simulate the medieval battle during the 24rd annual swordsmen gathering in Libusin village. (Photo by David W. Cerny/Reuters)

Mushers and theirs dog teams during the Sedivackuv long race, Orlicke Mountains, Czech Republic on January 28, 2016. The 240 Km (150 miles) race is a multi-day event, but was canceled today, two days early, because of poor snow conditions in the region. (Photo by David Tanecek/CTK via ZUMA Press)