Location
Germany
Status
Informal / Traditional
Suitable for
Adults only
Terrain
Grass / lawn
Best season
June to August
About Allnersee
The Allner See is a 10-hectare artificial lake on the southern edge of Hennef in the Rhein-Sieg district, created from a gravel pit dug from 1979 for the A560 motorway and landscaped by the town from 1986. It is about 420 by 230 metres and up to 7 metres deep, with no natural inflow or outflow, and lies in the Sieg meadows just south of the 15th-century Schloss Allner. A large mown lawn with some shade trees borders the water, the lake is stocked for anglers, and swimming and stand-up paddling are tolerated while other water sports are banned. It is not an official bathing water: there is no lifeguard, and swimming is at your own risk. Nude bathing is informal and contested. Naturist reports range from 'possible without problems' to 'almost impossible except at night', and one lake-guide commenter says nude sunbathing draws fines while another says discreet nude bathing works on the right-hand side of the lake close to the shore. On hot days hundreds of people crowd the meadow; the town once counted 800 to 1,000 visitors on summer days and closed the lake temporarily in 2020.
Getting there
From the A560 take the Hennef-West exit, head towards Waldbröl, turn left at the first traffic lights and then take the next left. Parking near the lake is limited and visitors report tickets for illegal parking. By train, get off at Hennef (Sieg) station and walk about 1.5 km through the town centre and over the Horstmann footbridge across the Sieg meadows; cycling is the easiest way to arrive. The lawn is level and reached on paths.
What visitors say
Opinions are sharply divided. Some describe clean, fresh water, a regularly mown lawn and few problems with discreet nude bathing; others report an overcrowded, littered meadow with dogs, loud music, smoking groups and parking tickets, and say nudity is practically impossible by day or is fined. Water quality is also disputed, with complaints in the past and praise more recently.
Summarised in our own words from public reviews and guides listed under Sources.
Amenities
Legal context
The lake is governed by the town's 'Satzung Allner See'; it is not a designated bathing water, boats and floats are banned and use is at your own risk. There is no FKK area, and reports conflict on whether nudity is tolerated or fined. In 2020 the town imposed a temporary swimming and access ban for infection control, upheld by the Cologne administrative court.
Naturism at Allnersee sits under Germany's rules for traditional tolerance — custom more than statute.
Full country law: Germany public nudity guide.
Researched 24 October 2026. No official source confirms naturist status, so treat it as unverified.
Location
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Approx. 50.7776, 7.2910
Visitor tips
- 1 Informal / tolerated site — be discreet and leave no drama.
- 2 Towel, water, sunscreen. Sit on your own towel.
- 3 No photos without clear consent.
- 4 Check access, tides, and parking before you go.
- 5 House rules and local custom can be stricter than the law.
More in Germany
Frequently asked questions
Can I bathe nude at the Allner See?
Only informally and discreetly; there is no FKK area, and some visitors report fines. Regulars suggest the right-hand side of the lake close to the shore.
Is swimming allowed?
Swimming is tolerated at your own risk, but the lake is not an official bathing water and has no lifeguard.
How do I get there by public transport?
Take the train to Hennef (Sieg) and walk about 1.5 km through town and over the Horstmann footbridge.
Is it busy?
Yes, on hot summer days the meadow gets very crowded, especially in the afternoon and at weekends.
Sources
Important
Beach status changes. Verify current conditions before you go. This is guidance, not legal advice.
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