Richard Llewellyn's book How Green Was My Valley, upon which the film is based, is set in Wales. Llewellyn claimed that it was based on his childhood experiences but after his death, it was discovered that Llewellyn was actually English and had spent little time in Wales. He did, however, gather his material by talking to local mining families in Gilfach Goch.

The film was not shot on location in Wales due to budget constraints; instead, the Welsh mining village was created on 80 acres in Brent's Crags near Malibu, California. In fact, the reason the film was shot in black and white instead of color was because the flowers of Southern California would not match those of Wales and the color of the countryside would not match the "green" mentioned in the title. According to publicity for the film, the set was so authentic that when the Welsh Choir that appears in the film arrived on the first day, they fell to their knees and wept.

Wales is a country that is part of the United Kingdom (along with England, Scotland and Northern Ireland). It is located on the southwestern part of the island of Great Britain and shares a border with England to the Northeast. As of the 2011 census, it had a population of over 3 million. The capitol of Wales is Cardiff (where many television shows are filmed, including Doctor Who and Torchwood).

Today it is regarded as one of the modern "Celtic Nations," becoming part of England in 1282 (though briefly winning independence in the 15th century). Although it is part of the United Kingdom, and shares many cultural affinities with neighbor England, it is officially listed as bilingual with half a million inhabitants speaking both English and Welsh (if you travel to Wales you can actually watch television in Welsh).
The country also competes separately from Great Britain in many international sports, including the FIFA World Cup and the Commonwealth Games (though not at the Olympics).

Perhaps the most famous local legend to come out of Wales is that of King Arthur. Multiple sites around Wales are believed to be connected to him, including Dinas Powys Hill Fort. Two Welsh lakes are also believed to be the final resting place of his iconic sword Excalibur--Llyn Llydaw and Llyn Ogwen.

The wizard Merlin (whose original Welsh name is Myrddin Wylt) is also believed to be of Welsh origin, with early texts putting his birth place in Carmarthen.