The exact derivation of the name "Harlech" is unclear. Some, mostly older sources derive it from Arddlech, i. e. ardd (high) + llech (rock), referring to the prominent crag on which the castle stands. Recent sources prefer a simpler derivation from the two Welsh words hardd (fair/fine) and llech (slate/rock).
As late as the 19th century some texts referred to "Harddlech" and "Harddlech Castle". This name appears in the mid-19th century translation of the Mabinogion: "And one afternoon he was at Harddlech in Ardudwy, at a court of his. And they were seated upon the rock of Harddlech overlooking the sea." Contemporary documents from the time of the Mabinogion do not mention Harlech, referring only to Llywelyn building his castle "at Ardudwy".
Theatr Harlech (formerly Theatr Ardudwy) is located on the Coleg Harlech campus and stages a varied selection of plays, music, and films throughout the year.
Other attractions in Harlech include its beach backed with sand dunes and the Royal Saint David's Golf Club, which hosted its fifth British Ladies Amateur in 2009. The Rhinogydd (or Rhinogs) range of mountains rises to the east.
In 2007, a LockheedP-38 Lightning (a World War II-era fighter aircraft) was rediscovered on Harlech beach. It has been described as "one of the most important WWII finds in recent history". The International Group for Historic Aircraft Recovery (TIGHAR) expressed an interest in salvaging the wreck of the U.S. Army Air Forces plane, known as the Maid of Harlech. However in August 2019, Cadw, the Welsh government's historic environment service, gave the remains scheduled status, making it the first legally designated military aircraft crash site in the UK to be protected for its historic and archaeological interest. The site is also controlled under the Protection of Military Remains Act 1986. The aircraft came down in September 1942 when it was on a gunnery practice mission. The pilot was Second Lt Robert F Elliott, 24, of Rich Square, North Carolina, who survived the crash, only to be reported missing in action a few months later.
Harlech has a Scout hut, which acts as a base for outdoor recreational activities.
In traditional and popular culture
A street in Harlech, Ffordd Pen Llech, had in 2019 been recognized by the Guinness World Records as the steepest residential street in the world with a gradient of 1:2.67 (37.45%), before Baldwin Street, in Dunedin, New Zealand was recognised with a gradient of 1:2.86 (35%). The steepness was determined by measuring consistently on the lower side of the street - the left or right, whichever was lower. It was later decided that consistently measuring in the middle of the street would be more correct. This gave Baldwin Street a gradient of 34.8% and Ffordd Pen Llech one of 28.6%, and so the title returned to Baldwin Street in New Zealand.