The Irish tale of Oisín describes the warrior’s journey to Tir na nÓg, the land of youth. He spends three years there but when he returns to Éire to see his old fighting comrades from the Fianna, 300 years have passed.
And for a related 🎵 interlude …
Tír na nÓg are an Irish folk duo formed in Dublin, Ireland, in 1969 by Leo O’Kelly and Sonny Condell.[^cite_ref-LarkinGE_1-0][1] They are often considered one of the first progressive folk bands with other artists like Nick Drake or groups like Pentangle.
💬 Wikipedia
Not to be confused with Horslips - who along with Tír na nÓg were in constant circulation on ‘young John’s’ turntable back in the day. Almost certainly arrived at them via Pentangle and Fairport - but most definitely stood on their own. Still listen to Horslips to this day - not so much Tír na nÓg.