Parkes Castle in Co. Leitrim, known as Ireland's most impressively restored castle.WikiCommons

There are over 30,000 castles and castle ruins in the Emerald Isle, with the oldest dating back to the 11th century. Spanning all counties, each has a unique, superlative and defining reason for being on today’s must-see list.

Bunratty Castle in Co. Clare still holds two medieval banquets nightly; Parkes Castle in Co. Leitrim is most impressively restored; Kilbrittain Castle in Co. Cork, built in 1035, is the oldest inhabited castle in the country.

Find out why Cahir Castle in Co. Tipperary has been regarded as the “safest castle in Ireland.”

The Ocean Sands Hotel in Co. Sligo created this detailed infographic on Ireland’s most interesting castles - see why they make the cut:

(And check out IrishCentral's gallery of beautiful Irish castles here)

*Originally published in November 2014.