Collecting returnable bottles and cans to make some money on the side is a popular sport in Denmark, peaking on hot summer days, with the City Hall Square in Copenhagen as its foremost arena.

The spacious shell-shaped square is lined with green benches, 80 in total, every other one equipped with a circular trash bin. That means 40 possibilities of finding empties that once contained beer or mineral water, fizzy drinks or alcopops. Most people don’t care about the deposit they paid, especially after drinking alcohol, the intake of which is another traditional Danish sport.

Searching for empties is a free-for-all. What it takes is a plastic bag or two. However, many work on a larger scale, sporting rucksacks and little trolleys. A certain degree of discretion is appropriate, but that comes automatically, as collecting is not exactly prestigious, although recycling is one side of it. Often, it’s a sport you choose out of necessity.

Copenhagen’s City Hall Square is a popular location for the lesser known Danish sport of collecting empty drink containers.

People on the benches react differently when the collectors approach: some look the other way, displaying embarrassment and disdain. Others get irritated because the relentless collectors never seem to tire and also empty out residue on the flagstones. A third group curiously follows the collectors’ endeavors, while a few drink up and hand them their beverage containers. Gathering reusables is definitely not a spectator sport.

About 1.7 million people live in the Greater Copenhagen area. Denmark’s capital is located on the eastern shore of the island of Zealand (Sjælland) and partly on the island of Amager. København — this is its Danish name — faces the Øresund, the strait of water that separates Denmark from Sweden and also connects the Baltic Sea with the North Sea.

The Rådhuspladsen, or City Hall Square, surrounded by fine old buildings up to six floors high with a few modern exceptions, is perfect for taking a break. Most spectacular is the City Hall, or Rådhustårnet, an elegant red brick building inspired by Italian Renaissance and completed in 1905. It sports the tallest spire (346 feet; 106 m) of all in this city of slender towers. The dark glass building opposite is an oversized ticket-office for the local yellow buses. But its most important function you will find downstairs: public toilets.

Good weather is not a matter of course in Copenhagen. Precipitation is evenly distributed over the year. On wet days, the City Hall Square is dominated by the flow of cars on either side of it and a stream of umbrellas moving across it between the pedestrian mall Stroget and Vesterbrogade Street. A large thermometer, adorning one street corner, fails to climb up to two decorative golden ladies — one on a bicycle, the other carrying an umbrella. The figurines are supposed to be out one at a time depending on the weather, which is so ever-changing and unpredictable that they often decide to stay in their doorways.