Capel Curig takes its name from the little St Julitta's Church in the ancient graveyard by the river bridge on the Llanberis road. This, confusingly, has been known for over 100 years as St Julitta's Church, and is currently being restored by the "Friends of Saint Julitta". Tradition claims this chapel to be the 6th-century foundation of St Curig, a Celtic bishop. Centuries later, probably when the present ancient church was built, the name appears to have been Latinised as Cyricus, which is the name of a 4th-century child martyr whose mother was Julitta. They are usually named together as Saints Quiricus and Julietta. The names Capel Kiryg and Capel Kerig were recorded in 1536 and 1578 respectively.
Approximately one kilometre from Pont Cyfyng, on the farm of Bryn Gefeiliau, there are the remains of a Roman fort and named Caer Llugwy by its excavators.. In 1920 excavations undertaken by J.P. Hall and Captain G.H. Hodgson revealed a roughly square Roman fort of approximately. Stone buildings were uncovered and traced. The rectangular walled area is on flat land close to the River Llugwy. From the pottery and finds in 1923 and subsequently, it appears to have only been garrisoned for 20–30 years.
Capel Curig is mentioned in the song Bottleneck at Capel Curig by cult UK band Half Man Half Biscuit on their album Trouble Over Bridgwater. Capel Curig is the setting for the climax of the 1956 thriller by Victor Canning.
Welsh language
According to the 2011 Census, 57.1% of the community's population aged 3 years or over could speak Welsh, with 82.5% of the Welsh-born population aged 3+ being able to speak Welsh. 54.3% of the community's population could speak Welsh in 2001. 49.5% of the community's population aged 3 years or over could speak, read and write Welsh in 2011.
Climate
As with much of the rest of the British Isles, Capel Curig experiences a temperate maritime climate, with warm summers and cold winters, little extremes of temperature and high humidity year round. The driest month is May, with around of rain, while the wettest is December, with more than of rain. The warmest recorded temperature was on 19 July 2006 and the coldest on 20 December 2010. Capel Curig is one of the wettest places in the UK and the wettest in Wales. Record high temperatures during February 2019 were higher than in the average summer: on 25 February 2019, Capel Curig recorded its warmest February day on record, with a temperature of. This was beaten again the next day, with.
Capel Curig was home to the botanist Evan Roberts. Roberts lived at Gelli, from where he explored all of Snowdonia, and compiled an unparalleled knowledge of the plant life of North Wales. Although he spent the first 40 years of his life as a quarry worker, he went on to become the colleague of academics. He was awarded the honorary degree of M.Sc. of the University of Wales, in 1956, at the same ceremony as the architect Frank Lloyd Wright, and his portrait was painted by Kyffin Williams.
