Born, Mountain summit in Solothurn, Switzerland

Born is a 719 m mountain in the Solothurn Jura, its summit on the territory of Wangen bei Olten, rising about 300 m above the surrounding valleys. The ridge is almost entirely wooded, with steeper slopes to the south toward the Aare and gentler inclines to the west and north. The Chessiloch, a tectonic cave, lies in the wooded southern slope.

The Born's flanks were worked for flint since the Stone Age, with settlement sites documented in Olten, Wangen bei Olten and Boningen. In the 20th century the Portlandcementwerk Olten quarried Jurassic limestone and marl on the north slope under a concession from the Bürgergemeinde Olten until 1996; the quarry is still in use.

The mountain served as a workplace for stone tool makers over many centuries. Visitors walking here can still notice the shallow pits scattered across the slopes where people once extracted raw materials.

The Tuusigerstägli, a staircase of 1,150 steps, climbs from the Aare between Aarburg and Ruppoldingen along the former pressure-pipe route of the Ruppoldingen-Born plant. It is also used for fitness training. The ridge is almost entirely wooded, and the Chessiloch cave lies in the wooded southern slope.

The wooded south slope hides the Chessiloch, a tectonic cave, and near the top of the Tuusigerstägli stairway lies the Heidechuchi, a cave-like rock cleft. The 1,150 steps of that stairway follow the former pressure pipe of the Ruppoldingen-Born pumped-storage plant, which stored Aare water in a basin on the plateau 320 metres above the canal and ran until 1960.