The village of Ballachulish (from Scottish Gaelic Baile a' Chaolais) in Lochaber, Highland, Scotland, is centred on former slate quarries. The name Ballachulish (Ballecheles, 1522 – Straits town) was more correctly applied to the area now called North Ballachulish, to the north of Loch Leven, but was usurped for the quarry villages at East Laroch and West Laroch, either side of the River Laroch, which were actually within Glencoe and South Ballachulish respectively.
The name Ballachulish (from Scottish Gaelic, Baile a' Chaolais) means "the Village by the Narrows". The narrows in question is Caolas Mhic Phàdraig - Peter or Patrick's son's narrows, at the mouth of Loch Leven. As there was no road to the head of Loch Leven until 1927, the Ballachulish Ferry, established in 1733, and those at Invercoe/Callert and Caolas na Con were essential. The Ballachulish ferry closed in December 1975 when the Ballachulish Bridge finally opened.
The Ballachulish Hotel and Ballachulish House (until recently  a country house hotel) are located near the narrows at (south) Ballachulish Ferry rather than in the "modern" village some 3 miles (5 km) east. Ballachulish House was reputed to be haunted, and the drive leading to it was ridden by a headless horseman.
The hamlet of Glenachulish lies in Gleann a' Chaolais, the glen that runs down to the narrows. This is the subject of the Gaelic song, Gleann Bhaile Chaoil written by John Cameron (1865–1951) and known locally both as the Paisley Bard and by his local nickname Iain Cealaidh. He is often confused with another local bard also called John Cameron, known locally as Iain Rob (1822–1898). Gleann a' Chaolais is ringed by Beinn a' Bheithir, a massif which contains two munros - Sgorr Dhearg and Sgorr Dhonuill. In recent years a number of new houses have been built locally along with holiday chalets and an art gallery. Also the fields of Gleann a' Chaolais have been turned into the 9-hole Dragon's Tooth golf course.
Overlooking the narrows is the monument to James of the Glen, "hanged on this spot for a crime of which he was not guilty". Robert Louis Stevenson based his novel Kidnapped around the story of the Appin Murder. Whoever did kill The Red Fox (Campbell of Glenure) is still not known.
The 50 Postal numeral was also used on the Ballachulish Ferry and by the Ballachulish Quarry