- Ffordd Pen Llech
- 1:2.67 ratio
- United Kingdom (Harlech)
The steepest street (road) is Ffordd Pen Llech, in Harlech, Wales, UK, with a gradient of 1:2.67 (37.45% stretch over fall), as verified on 6 June 2019.
The record measurement is based on the highest gradient over a 10 m (32 ft 9.7 in) section of road. Ffordd Pen Llech contains residential properties, a shop, a restaurant, a caravan park and laundry service, as well as the UNESCO World Heritage site of Harlech Castle.