The path was opened in 2007, and includes the 10,000th mile of cycle path in the UK. The nearby Sanger institute (famous for its genome sequencing) suggested to decorate the path with a gene, and BRCA2 was chosen because it also has approximately 10,000 base pairs, but also because it's a gene that people can relate to. Genetic screens for breast cancer risk are something that people will have heard of, and this is the gene that those tests look at.
Amsen has pictures of the path which give a good impression of the scale. What an interesting way to personalize the information in a genome; I wonder if the positions of mutational variants are marked?