Professor Korner has generously supported school mathematics for more than 30 years and has been a good friend to NRICH since it started.
A review of the website http://www.bangor.ac.uk/cpm/exhib/
Some puzzles requiring no knowledge of knot theory, just a careful inspection of the patterns. A glimpse of the classification of knots, prime knots, crossing numbers and knot arithmetic.
Published May 2001,February 2011.