Harju Park occupies the pine-forested ridge that runs through the western part of central Jyväskylä, giving the city its most dramatic natural feature — a sandy esker ridge rising sharply above the surrounding streets. The park has been a recreational area since the 19th century and is still the city's most used green space, with paths running through the pines and an observation tower at the top offering views over the city and the surrounding lakes.
The ridge is a classic example of a Finnish esker — a long ridge of sand and gravel deposited by meltwater flowing beneath the retreating ice sheet at the end of the last Ice Age. The pine forest that covers it is fragrant and light, quite unlike the denser mixed forests on lower ground. In summer, the paths fill with joggers and families; in winter, a modest ski slope operates on one of the steeper faces. The park is a ten-minute walk from the market square.