Glencastle is situated approximately three miles east of Belmullet, on the main Bangor-Belmullet road.
Local folklore tells of the Glen as the only route into the north-west of Erris, where giants would close the gates at night, levying tolls on travellers. The local legends still refer to the giants buried beneath the hills in the centre of the Glen.
A castle was established here in the sixteenth century by the Barratt clan, after a long period of struggle with the O’Connors.
Throughout the 17th and 18th centuries, Glencastle was frequently fought over, changing hands on several occasions. At some stage during this time, the castle fell into disrepair, possibly when the Bangor to Belmullet road was being constructed. An ancient dolmen was certainly lost during this process, when the engineers refused to divert the route by a matter of feet.
The Atkinsons, a Dublin family, owned large tracts of land around the Glencastle region. Throughout the latter part of the nineteenth century, they found themselves at loggerheads with the Repeal Movement, which was set up by Daniel O’Connell to repeal the Act of Union and set up an Irish Parliament. The Repealers were extremely active in the Erris area at this time, and in 1898 they were succeeded by the United Irish League, whose motto was 'Land for the People'. In conjunction with the local clergy, they eventually persuaded the Atkinson family to sell their estate to the Congested Districts board for division amongst the tenants.
In 1820 a new chapel named Cill Mhuire, was constructed in Glencastle, alongside the newly completed Belmullet - Bangor road. This was built by stone masons from Tyrawley, while the parishioners roofed and thatched the roof. By the early 1830’s, according to the 1831 census, the local congregation had reached over nine hundred strong. By the middle of the twentieth century, however, a new church was deemed necessary, and a new church was opened in July 1959.
The first National School in Glencastle was built in 1857. It consisted of just one room and had an attendance of forty-two pupils. By the year 1874, there were 277 pupils on the Roll, although the attendance was rarely more than one hundred. In 1887, a new school was built to accommodate these growing numbers, opening a year later. In the early years of the twentieth century evening classes for men were introduced.
Glencastle currently has a church, one public house, and a small shop, as well as a number of dwelling houses.
By Tony Conway
Where the Sun Sets by Father Seán Noone
A Various Country - Essays in Mayo History - edited by Raymond Gillespie and Gerard Moran
The Heritage of Mayo by Áine ní Cheanainn
The Parishes in The Dioces of Killala by Father E. McHale