Dedicated to the memory of John Fitzgerald Kennedy, President of the United States from 1960 - 1963, the Arboretum has a plant collection of international standing. It covers 252 hectares (623 acres) on the southern slopes and summit of Slieve Coillte. It contains 4,500 types of trees and shrubs from all temperate regions of the world, planted in botanical sequence. There are 200 forest plots grouped by continent.

A road provides access to the summit at 271m from which there are panoramic views.

A Visitor Centre houses exhibitions and audio visual show. Access for people with disabilities.