Founded in 1932, it was recognized as a UNESCO biosphere reserve in 1981. It occupies over 10 thousand ha, including the Killarney Lakes area. The highest parts are difficult to access and are a refuge for the European deer. The most interesting plant community is a species-pure yew forest, one of three in Europe.
There is the highest peak in the country - Carrauntoohil at a height of 1041 m above sea level, as well as numerous wetlands, reservoirs, lakes, meadows, and forests.
In the park, you can admire the atmospheric Ross Castle, the long-time seat of the O'Donoghue clan - the last stronghold in Ireland that still resisted Oliver Cromwell during his bloody campaign in the 17th century.