Sissacherfluh Castle (Ruin)

The Refugium Sissacherfluh is a defensive structure in the Ergolz Valley in the Swiss canton of Basel-Landschaft.

Barely 2 kilometers north of Sissach, on the rocks of the widely visible Sissacher Fluh, lie the remains of the Refugium Sissacherfluh. The complex is protected on the southeast, south, and west sides by vertical rock faces and steep terrain. It is easily accessible from Sissach or the Sissacherfluh bus station via hiking and footpaths and offers a magnificent view as far as the Alps (viewpoint with panorama board).

The Sissacherfluh defensive structure was used in several phases over millennia: accordingly, traces of older installations have been heavily disturbed. Roughly, the following periods of use and expansion can be identified:

• A first use likely occurred in the late Bronze Age. Few remains of post houses from this period were discovered in the western part of the complex.
• The main use probably took place in the Early Middle Ages: A 2-meter-thick defensive wall (double-shelled with earth filling) with a gate and tower at the northern corners was built on the gently sloping north side to protect the entire area of 2.8 hectares. This must have been much higher than the conserved remains suggest today, as stair pillars were added at regular intervals on the inside, allowing for rapid manning of the wall walk on the wall.
• The last use from the Thirty Years' War onwards: A high watchtower was built as part of the Swiss warning and reporting system. Stone wall squares near the Fluh at the viewpoint are still preserved from this. This high watchtower was probably protected by the now flattened but still clearly visible double rampart around the outermost end of the Fluh: Meyer suspects that this double rampart already existed in the Early Middle Ages and was restored for the high watchtower.

Since the essential parts of the complex date from prehistoric times (no written records), little is known about its history. In 1936, the complex – as part of the cantonal labor camp (employment program for the unemployed) – was largely excavated, which proved difficult and costly due to the large area.