Climbing "Route: 21" (graded 4+) in Knorren Sonderlinge is a delightful experience, offering a blend of accessible difficulty and interesting rock formations. The 4+ grade makes it a good option for climbers who are relatively new to outdoor climbing or looking for a warm-up route. The rock quality in Knorren Sonderlinge is generally excellent, providing good friction and reliable holds. While the route itself might not be overly long, it often features interesting sequences and requires careful footwork. Expect to encounter some small crimps, positive edges, and maybe even a bit of stemming. The setting within the Knorren Sonderlinge area is also very rewarding, with beautiful views and a generally peaceful atmosphere. Overall, "Route: 21" is a fun and enjoyable climb that provides a good introduction to the climbing in this unique area of rock.