And how did they end up on the roof?
Up on the roof of the town hall, you can spot two polar bears. The architect Martin Nyrop decided to have these there, but it was not entirely popular. He was even scolded for this! The perception was that there would be figures from antiquity on the roof and nothing else. By the way, the bears refer to Greenland, which was a Danish colony when the town hall was built.
Also, they are carved on the island of Bornholm.