Killary Harbour, An Caoláire Rua in Irish, is the Republic of Ireland’s only fjord, which forms a natural border between counties Galway and Mayo. It is 16 kilometres long and in the centre over 45 metres deep. On its northern shore lies the stunning mountain of Mweelrea, Connacht's highest mountain, rising to 814 metres. Two other fjords in Northern Ireland are Lough Swilly and Carlingford Lough.

The unspoilt wilderness of the area is enriched by the many contrasts that its natural landscape offers, from the cool blue of the ocean to the deep green of the hills in summer, and from the deep purple heathers to the russet autumn mountains that surround this tranquil haven.

At the head of Killary Harbour there is Aasleagh Falls, a beautiful waterfall, here the Erriff tumbles down a couple of metres before flowing into the sea; the scenery is wild and unforgettable.