Gouda (say it 'How-da') is the most famous Dutch cheese. It is a hard, yellow cheese that ages for months in special wooden warehouses, slowly developing a sharper flavour. Edam is another famous one - smaller, round, and traditionally covered in red wax.
At the cheese markets, the cheeses are laid out in rows on the square. Buyers walk among them, sniffing, squeezing and tasting tiny samples from a special pointy tool. Once they decide on a price, the buyer and seller clap each other's hand - this hand slap means 'deal done', and the price is set.
The cheese porters then run the wheels across the square on wooden barrows that look a bit like ladders. Each pair of porters carries about 160 kilograms of cheese at a time - heavier than two grown-ups. They wear special white outfits and coloured straw hats so people know which team they are on.
The Netherlands is one of the biggest cheese exporters in the world. Dutch dairy farmers and their black-and-white Friesian cows make over 950 million kilograms of cheese every year - enough to give every person in the world a chunk.