Hötorget, or directly translated into english the hay square, has been a known place for markets since the 17th century.
Today it is one of few places that has a bigg gathering of market stalls in central Stockholm. Located as central as you can get this small square also becomes a bit of a welcome break in the normal modern city landscape.
Fruit, vegetables and flowers are the main sellers. Every evening each stall closes and moves leaving the square empty just to be opened early the next day.