Aargau is a canton of castles, rivers and old industry, and that is exactly what shapes its abandoned places. Our database has 81 Lost Places geolocated here: an empty Baroque palace on Lake Hallwil and dozens of medieval castle ruins that have been decaying in the woods for centuries.
This article is part of our dossier on the Lost Places of Switzerland. The terms Lost Places Aargau, abandoned places in Aargau and urbex Aargau all mean the same thing. Under each spot there is an Add to map button that drops the GPS coordinates into your profile for free, with no credit card.
Key takeaways: Aargau counts 81 geolocated Lost Places. This article presents 4 dated sites, from a Baroque palace to a medieval castle ruin. Free GPS under each spot.
1. Brestenberg Palace: the Sleeping Beauty of Lake Hallwil
Photo: Alexey M., CC BY-SA 4.0, via Wikimedia Commons.
Brestenberg Palace is an empty Baroque palace on the western shore of Lake Hallwil, in the municipality of Seengen. In 1622, Dean Samuel Gruner sold the estate for 4,500 guilders to Hans Rudolf von Hallwyl, who had it rebuilt in 1625 as a Baroque country residence. In 1844, Adolf Erismann converted the building into a hydrotherapy spa, which drew guests from all over Europe to the lakeside. After the spa era ended, Brestenberg served as a hotel until the mid-20th century, followed by a long vacancy. It now belongs to the SKKG foundation, which is gradually introducing interim uses; the palace has been neither demolished nor thoroughly renovated, and access is not public.
Discover all the abandoned places in Aargau on the urbex map.
2. The Alt-Wartburg ruin: the castle Bern burned down
Photo: Paebi, CC BY-SA 3.0, via Wikimedia Commons.
The Alt-Wartburg ruin is a medieval hilltop castle on the Wartberg above Oftringen. Built shortly before 1200 by the lords of Ifenthal, its construction was completed around 1325. When the Confederates conquered Aargau in 1415, Bernese troops burned the castle down; it has been a ruin ever since. From 1966 to 1967, the site was archaeologically excavated and secured. Today it is a freely accessible ruin in the woods, never built over, a classic destination for castle enthusiasts and photographers.
Discover all the abandoned places in Aargau on the urbex map.
3. The Iberg ruin: an unfinished castle near Brugg
Photo: Badener, CC BY 3.0, via Wikimedia Commons.
The Iberg ruin is the ruin of a hilltop castle on the Iberg, overlooking the Aare valley near Riniken, close to Brugg. Built in the 11th century, probably by the Habsburgs or a Habsburg vassal, it was abandoned around 1200 after a fire. An unfinished tower and unused ditches bear witness to an aborted reconstruction. Test excavations and conservation work took place in 1997; today only a few wall remains are visible, a quiet archaeological monument above the river.
Discover all the abandoned places in Aargau on the urbex map.
4. The Königstein ruin: from noble seat to bare ruin
Photo: Arkelin, CC BY 4.0, via Wikimedia Commons.
The Königstein ruin is a hilltop castle ruin on the Brunneberg above Küttigen, in the Folded Jura. Built in 1277 by the lords of Kienberg-Küngstein, the castle was sold in 1417 to the town of Aarau and abandoned shortly afterwards; by 1454 it was already heavily decayed. Today only meagre remains survive, high above the Bänkerklus, a place for hikers and history buffs.
Discover all the abandoned places in Aargau on the urbex map.
More Lost Places in the canton of Aargau
Beyond these four sites, our map lists many more freely accessible spots in Aargau, from old farmsteads to industrial wastelands along the Aare. Add them straight to your own map:
Lost Places in Aargau at a glance
| Site | Type | Built | Status 2026 |
|---|---|---|---|
| Brestenberg Palace | Baroque palace | 1625 | empty, SKKG foundation |
| Alt-Wartburg ruin | Castle ruin | around 1200 | ruin since 1415 |
| Iberg ruin | Castle ruin | 11th century | ruin since around 1200 |
| Königstein ruin | Castle ruin | 1277 | ruin since after 1417 |
What is the most famous Lost Place in Aargau?
The best-known single site is Brestenberg Palace on Lake Hallwil, an empty Baroque palace with its own spa history. Added to this are numerous medieval castle ruins such as Alt-Wartburg, Iberg and Königstein.
Why does Aargau have so many castle ruins?
In the Middle Ages, Aargau was dense Habsburg heartland with many noble seats. During the Confederate conquest of 1415, several castles were destroyed or abandoned; they survived as ruins and are today freely accessible witnesses to history.
Is urbex legal in Aargau?
Looking and photographing from the outside is allowed. Entering someone else's buildings or fenced grounds is trespassing under Article 186 of the Criminal Code. Open castle ruins like Alt-Wartburg, on the other hand, are usually freely accessible.
Where do I find the coordinates of the Aargau spots?
Under each spot in this article there is a free button. The full Aargau map shows all 81 locations.
Conclusion
Aargau combines an empty Baroque palace with a dense landscape of medieval castle ruins, from Alt-Wartburg to Königstein. You will find more locations on the Aargau urbex map and in the dossier on the Lost Places of Switzerland. Always with respect for the place and for property.