The two highest mountains in Donegal, Errigal and Slieve Snaght, overlook 40,000 acres of mountains, glens, lakes, and woodlands, and the 19th-century splendour of a neo-Gothic castle amid magnificent gardens. Named for the spectacular valley of the Glen of the Birches, or Glenveigh (Gleann Bheatha), this park is home to red deer, badgers, foxes, stoats, peregrine falcons, and merlins, and remnants of the deciduous woodlands that once covered the land. There are native brown trout and salmon in Lough Veagh, and the passage of glaciers is written on the cliffs of the Poisoned Glen.

Activities include day hiking, fishing, exploring the Glenveagh Castle and grounds, and watching the largest herd of red deer in Ireland.

• Hike the mountain trails, and catch a glimpse of the largest herd of red deer in Ireland.
• Take a guided tour of the 19th-century Glenveagh Castle, a neo-Gothic castle in the Scottish style.
• Roam the oak woodlands that surround Lough Veagh.