Sprinkled with small islands, the 350-hectare Lough Key Forest Park, 4km east of Boyle, shelters picturesque ruins including a 12th-century abbey on tiny Trinity Island and a 19th-century castle on Castle Island. It's a favourite with families for its wishing chair, bog gardens, fairy bridge and viewing tower. Marked walking trails wind through the park.
Bus Éireann services from Sligo to Dublin stop here; in July and August, shuttle buses run from King House.
The park was once part of the Rockingham estate, owned by the King family from the 17th century until 1957. Rockingham House, designed by John Nash, was destroyed by a fire in the same year; all that remains are some stables, outbuildings and eerie tunnels leading to the lake – built to hide the servants from view.
There is an informative visitor centre, and the Lough Key Experience (adult/child €8/5), incorporating a panoramic, 300m-long treetop canopy walk, which rises 9m above the woodland floor with sweeping lake views. Other attractions include the Boda Borg Challenge (€19; minimum three people), a series of rooms filled with activities and puzzles (great for sudden bursts of rain), and an outdoor adventure playground (day pass €5).
Lough Key Boats runs cruises and hires row boats.