First-time visitors to the arboretum are best to begin at the reception centre, a rather inapposite municipal building lying close to the main car park. Here maps showing the location of different species in the collection can be inspected and a route planned. The layout reflects the underlying function of the arboretum as a research institution. Around 150 acres are divided into 250 forest plots, each devoted to a particular tree species and grouped together geographically. The remaining area of 310 acres is occupied by the plant collection which is laid out in botanical sequence with three examples of every species represented. Each plant is recorded on a grid system, has its own record card and is well labelled. There are two botanical circuits, one of Gymnospermae (conifers), the other of Angiospermae (broadleaves); the groups have been cleverly interwoven to improve the appearance of the collection by providing colour throughout the year.

Visitors should anticipate a walk of at least two miles around the main circular route, while demon dendrologists may find themselves trekking ten miles or more. Taking the principal arboretum road eastwards from the visitor centre, enthusiasts should inspect the Phenological Garden on the left where the relationship between climate and biological phenomena, such as plant flowering, is researched. Further along, the eucalyptus collection on the other side of the walk has yet to be completed; it includes some fine varieties: E. cordata with its smooth white bark and E. nirens, the silver-top gum.

Passing through groves of silver fir, the visitor arrives next at the Ericaceous Garden which occupies much of the eastern part of the arboretum. In addition to a wide variety of heathers, pieris and other peat loving plants, there are more than 500 rhododendron species and hybrids in this area. These constitute a splendid collection, all presented in an inventive way with something for all seasons.

In the southern sector of the arboretum the walk curves around a small lake; here a lush display of waterside plants and an island of gunnera greet the eye. On the east side of the lake above the main path are many fine magnolias, while on the opposite side lies an extensive collection of cherries providing a glorious mass of colour in early spring. A pleasant walk can be made through the cherries, beyond which is an impressive vista up to the reception centre. The main route, however, goes further south, passing an array of cotoneasters as well as many crataegus and sorbus varieties.

The rocky Alpine Garden, covering about one acre, is the main feature in the western sector of the arboretum. This bed contains a colourful planting of over 320 varieties of dwarf and slow-growing conifers which should not be missed. Further north an extensive area of maple cultivars and a good poplar collection have been laid out. Here in the North-East American plots, the Eastern American plots and the South American and Australian plots conifers and other species of trees enjoy the high sun-duration of this part of Ireland. A drive to the summit of Slieve Coillte to a viewing station at 630 feet will give a magnificent panorama of the whole arboretum and the countryside beyond - a fitting end to a rewarding expedition.