A venerable old tune. The earliest transcription I have is in The Petrie Collection of the Ancient Music of Ireland , first published in 1855. It is also the first tune in the first set on the first Bothy Band LP (1975) which, to me, adds to its venerableness.
Kesh is a village in County Fermanagh, Northern Ireland. Toponymically, Kesh is an Anglicisation of ceis, meaning ‘a wicker bridge’ in Irish. An alternative title for the tune is The Castle, most likely a reference to Crevenish Castle, the remains of which are just outside the village.