It is the most extensive Stone Age monument in the world with dwelling houses, tombs and stone walled field systems. There is a visitor centre on site which is open from late April until late October and which is about eight kilometres west of Ballycastle (Irish: Baile an Chaisil) on the R314 in the north of County Mayo, Ireland (Irish: Contae Mhaigh Eo, Éire). This is an extremely important archaeological site. Ceide Fields is a field system and settlements site dating to 3000BC and before.