Why it's impossible to measure England's coastline

A new hiking trail will soon allow travellers to walk around England's entire coast – but a strange paradox means no one knows exactly how long it is. Last month, King Charles III inaugurated a new hiking path that will soon stretch around the entire coast of England. The project is roughly 80% complete, and when it fully opens later this year, the King Charles III England Coast Path will become the longest managed coastal walking path in the world. The 2,689-mile-long (4,327km) ramble connects the granite cliffs of Cornwall with the rolling sand dunes of Northumberland and East Sussex's iconic white chalk cliffs, allowing travellers to explore England's extensive shoreline step by step. But while the length of the newly designed path is easily measurable, the coastline that it follows is not. England's coast is often measured as part of the UK's, but look up how long that is and you'll get wildly different answers from various reputable organisations. The CIA World Factbook lists the UK's coastline as 7,723 miles (12,429km), while The World Resources Institute measures it at 12,251 miles (19,716km) – a discrepancy of more than 4,500 miles (7,242km). "The thing is, no one really kn