A short distance east of Boyle lies the Lough Key Forest Park, part of the Rockingham estate, an enormous demesne which once belonged to the King family (Edward King, drowned in the Irish sea in 1636, was the subject of Milton's elegiac poem Lycidas). Rockingham originally belonged to the MacDermots, the local chieftans and Lords of Moylurg, but was handed to the King family in 1617. The big house in what is now the forest park was burned down in 1957, but King House, the family's town mansion in the main street, can be visited.
Lying in the grounds of the former Rockingham estate, the Lough Key Forest Park ranges over about 340 hectares along a lake shore and includes a cypress grove, deerpark, ice-house, temple, bog garden full of peat loving plants such as azaleas, and many waymarked paths. Boats tour the lake from Rockingham Harbour, and rowing boats can be hired. There are ring-forts and islands to explore, and a vantage point called the Moylurg Tower can be climbed for views of the surrounding scenery.