The World's Steepest Street Run on Saturday, 4 April 2020 features a 37.45% maximum gradient on Ffordd Pen LLech in Harlech.
The 5km route starts at the foot of the castle. As you bear round the first corner Ffordd Pen Llech looms in front of you rising over 50 metres along its 322-metre length and disappearing round its first bend like a rollercoaster that leaves you wondering what's to come. This first bend is the steepest part, but there's no rest for the wicked (or slightly crazy) as you continue to the top of the street and over the high street before finally reaching the top of Harlech with views out to the sea. Finally you can let momentum take over as you head back down through the town and past the historic castle to the finish line.