The Karussell consists of two concentric surfaces:
The upper (outer) asphalt road — a normal-camber 180° left-hander with no significant banking. Used in slow vintage cars, motorcycles, tourist drives and rain conditions.
The lower (inner) concrete trough — a heavily-banked half-pipe carved below road grade, with the apex banked at around 27 degrees. Used by racing cars and confident drivers because it produces dramatically higher lateral grip and a much shorter line.
The driver chooses which groove to use entering the corner. Modern racing convention is to dip into the inner concrete trough — "drop into the Karussell" — which the cars do with a marked vertical wheelbase compression as the inside wheels fall lower than the outside.
The Karussell did not exist as such when the Nordschleife opened in 1927. The corner was originally a single-camber 180° turn that drivers found easy to gain lap-time on by riding the outer edge of the asphalt. By the 1930s, drivers had begun to use the inside of the corner — a drainage area that happened to be slightly concave — as a faster, more grippy line. The track surface there gradually became worn and bowl-shaped from repeated use.
The corner's name is generally believed to date to the 1931 German Grand Prix, in which Rudolf Caracciola drove a Mercedes SSKL through the corner using the inner drainage groove so consistently that the lap time was decisively faster than rivals' attempts on the conventional racing line. The corner was named the "Caracciola-Karussell" in his honour during the 1930s.
In the post-war reconstruction of the Nordschleife (1948 onward), the bowl was formalised into a deliberately constructed banked concrete trough, with the radius and banking optimised for the racing groove. It has remained essentially unchanged since.
The Karussell is unique in international motorsport because it offers two valid, geometrically different racing lines, and the choice between them depends on the car's setup, the driver's confidence, and the conditions. No other corner on the FIA Grade-1 calendar offers this — the banked groove is a feature of an older era of racing geography that simply did not get sanded away during modernisation.
The Karussell punishes:
Ride-height-low cars — a car with insufficient ride height can scrape the concrete edge of the trough.
Stiff suspensions — the banked groove is bumpy; soft-suspended cars find a smoother ride.
Long wheelbases — modern Le Mans Hypercars and LMP2 prototypes find the radius tight; some drivers prefer the upper asphalt in those cars.
It rewards:
Mid-engine sports cars — Porsche 911 GT3, Mercedes-AMG GT3, Ferrari 296 GT3 — all of which take the inner groove confidently.
Touring cars and historic cars — the original Karussell users.
In the Nürburgring 24 Hours and other endurance events on the full Nordschleife combined-24h layout, the Karussell remains a defining feature of the lap. The famous in-car footage of a Manthey Racing Porsche 911 dipping into the trough at full speed — a sustained right-handed lateral g-load with the steering wheel almost in full lock — is one of the most-circulated images of GT3 racing on the Nordschleife.
The corner is unaltered between the 1948 reconstruction and the present day. There are minor surface re-profilings every few years (the concrete edges chip; the asphalt rim wears) but the geometry has remained constant for more than 75 years.
Less famously, there is a kleine Karussell ("little Karussell") further around the Nordschleife lap — a smaller banked left-hander between Hohe-Acht and Brünnchen, also banked though not as dramatically. The kleine Karussell is sometimes confused with the main Karussell in older racing footage. Both are named in the corner database, and modern broadcasting always disambiguates.
The Karussell is in Assetto Corsa's ks_nordschleife (DLC, laser-scanned), iRacing's nurburgring/nordschleife, AMS2's Nurburgring_Nordschleife, and ACC's nurburgring_24h (Intercontinental DLC). The banked geometry is one of the standard tests of a sim's tyre and suspension model — the way the car drops into the trough and how the chassis behaves on the inner groove is a known indicator of physics fidelity.