The Obere Ilz nature reserve is one of the most pristine river valleys in south-eastern Bavaria — 380 hectares of wild, unspoilt landscape where the dark, tea-coloured waters of the Ilz river wind through ancient forest and rocky gorges. If you are looking for a place where nature feels genuinely untouched, this is it.

Known as the 'black pearl of the Bavarian Forest', the Ilz owes its characteristic dark hue to the soft, peaty water draining from the highlands between the mountains of Rachel (1,453 m) and Lusen (1,373 m). The valley cuts deep through the forest, offering a varied terrain of riverside paths, mossy boulders, historic mill ruins and the atmospheric remains of Dießenstein castle. Spring brings lush green banks and wildflowers; summer offers cool shade and the soundtrack of rushing water; autumn transforms the valley into a canvas of gold and amber; and winter wraps everything in fog and silence. The area is home to over 20,000 animal species, including kingfisher, dipper and the rare river pearl mussel.

• Saldenburg municipality (near Dießensteiner Mühle) — riverside trail, moderate difficulty, recommended starting point for the reserve.
• Fürsteneck — access from the Wolfsteiner Ohe valley side; the Ilztalbahn train line connects Passau to Fürsteneck, making car-free access straightforward.

• Obere Ilz is a designated nature reserve (380 ha) — stay on marked paths and respect wildlife protection rules.
• Kayaking and canoeing are permitted only on specific sections and during defined periods; current rules are published by the Bayerischer Kanu-Verband.
• Fishing is allowed on selected stretches with a permit; the prized huchen (Danube salmon) may only be taken once per angler per season and must measure over 90 cm.
• The reserve is open year-round.

The Ilz valley was named River Landscape of the Year 2002/2003 — a recognition of its exceptional ecological value and the community efforts to protect it after a swimming ban was introduced in 1991.