Yr Wyddfa, Mountain summit in Gwynedd, Wales

Snowdon is a summit of volcanic rock in Gwynedd, Wales, rising to 1085 meters (3560 feet). Five connected peaks form sharp ridges with glacial basins opening between them.

The name Snowdon appears in 1095 as Snawdune, Old English for "snow hill". The Welsh name Yr Wyddfa is recorded in a Latin charter of Aberconwy Abbey dated 1198, though some scholars place it in the early 13th century or after Edward I's conquest of Gwynedd in 1282–3. In November 2022 the national park authority adopted Yr Wyddfa alone.

The Welsh name Yr Wyddfa comes from gwyddfa, meaning height or promontory, which later also took the sense of burial cairn. Legend holds that the giant Rhita is buried under the summit cairn, defeated by King Arthur in one version and killed by the giant Idris in another. In November 2022 the national park authority moved to use Yr Wyddfa exclusively, and in November 2024 it kept the name after businesses and media adopted it.

Six different routes lead to the top, with the Llanberis route covering 7.2 kilometers (4.5 miles) and climbing 975 meters (3200 feet). Weather conditions can shift quickly, so preparing with appropriate gear makes the visit safer.

The summit station sits just below the peak and holds a restaurant and souvenir shop, reached by a rack railway that runs 7.6 km from Llanberis. The line opened in 1896 and carried 98,567 passengers in 2021.