Lostorf lies at the foot of the Jura Mountains between Olten and Aarau. The village is nestled in a charming landscape, away from busy transport routes. The Lostorfer Bach also shapes its geographical setting: formerly a linear village along the stream, Lostorf stretches along both sides of the watercourse in a valley basin, at the northern edge of the Aare lowlands in the Niederamt district of the canton of Solothurn. Village history, religious buildings and woodland themes offer different ways to explore the area.
History of the cross, chapels and castle
The original Mahrer Cross was built around 1620 and was probably a plague cross. The cross that now stands at the edge of Balmiswald is an exact replica, erected in 1958. It also played a role in the village’s history as a place of pilgrimage: thousands of sick people, particularly from the regions of Solothurn, Aargau and Basel, visited the cross. Its history thus connects a place in Lostorf with visitors from several regions.
The Antonius Chapel in Mahren was built in 1950 as a simple wayside chapel, based on plans by Werner Guldimann. Its colourful stained-glass windows depict the Creator surrounded by the four elements: earth, air, fire and water. Lostorf Reformed Church was built in 1967/68 to plans by the Solothurn architect Bader. Another small place of worship is the Bad Chapel, located close to the spa.
The Lostorf Village Museum is housed in a former day labourer’s cottage, built between the late 18th and early 19th centuries. Across three floors of renovated rooms, visitors can see how families lived in the past. Wartenfels Castle, meanwhile, is a landmark of Lostorf. The village brings together a range of historical themes: a former pilgrimage cross, chapels and churches, and a museum offering insights into family life in earlier times.
Woods, trails and activities
The way the forests are managed is also part of the story of the village. The Lostorf citizens’ community has concluded four forest reserve agreements with the canton of Solothurn, covering a total area of 66 hectares. The agreements are long-term. In the forest reserves, trees can grow old, die and decompose without human intervention. This creates an undisturbed habitat for plants and animals.
There is an easy-to-walk 1.3-kilometre nature trail in the Schlossgasse area. Various hiking routes also start from Lostorf; check the conditions for the routes you plan to take before setting off. Lostorf is also on national cycle route 5, the Mittelland Route. Check the signage and route before you ride. Another activity is available at Heidental Golf Course, an 18-hole course in attractive surroundings.
Seasonal events and visiting times
In spring, the Buechehof’s large organic seedling market offers vegetables, salads, flowers and many rare varieties. The Buechehof Whit Monday matinée includes a hearty brunch and the opportunity to explore the Buechehof grounds on a guided walk. These seasonal events add specific opportunities to visit at certain times of the year to the area’s historical and natural attractions.
The following opening hours apply to the castle courtyard and museum at Wartenfels Castle in 2026: Sundays from 1 pm to 5 pm, from 3 May to 18 October. If you are planning a visit outside this period, check the dates for the relevant season. This helps distinguish the castle’s seasonal opening hours from Lostorf’s features described as available year-round.
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