Baldwin Street in Dunedin, New Zealand, may be the steepest residential street in the world; it reportedly averages 1:3.41 (16.33° or 29.3%) for 161 meters but its maximum is claimed to be 35% for an unknown distance. Canton Avenue in Pittsburgh is said to have a 37% grade; the length of that grade is unknown.

The title for the steepest street in the world is currently held by Dunedin, New Zealand, for Baldwin Street. After a brief period where the title was awarded to Ffordd Pen Llech in Harlech, Wales, the Guinness World Records officially reinstated Baldwin Street as the record holder in 2020 following a formal appeal and re-measurement. The street has a maximum gradient of 34.8%, meaning for every 2.86 meters traveled horizontally, the elevation rises by 1 meter. The street is so steep that it is paved with concrete rather than asphalt, as bitumen would melt and slide down the hill on a hot summer day. In 2026, Baldwin Street remains a major tourist attraction, with visitors from around the world attempting to walk to the top or participating in the annual "Jaffa Race," where thousands of spherical chocolate candies are rolled down the slope. While other cities like San Francisco (Filbert Street) and Pittsburgh (Canton Avenue) claim high gradients, none officially match the rigorous measurement of Dunedin's famous residential road, which continues to challenge the calves of locals and tourists alike.