This thickly wooded valley is peaceful now, but its history is dark. Nestling at its heart, Glenveagh Castle was originally the home of the infamously cruel landlord John George Adair, who evicted scores of struggling tenant farmers in the freezing winter of 1861, leaving many to die, ostensibly because their presence on his estate was ruining his view. If the tale is true, it’s divine justice that his estate now belongs to all of the people of Ireland. Today the fairy-tale setting includes woodlands, herds of red deer, alpine gardens, a crystal-clear lake, and the highest mountain in Donegal, Mount Errigal. There’s a visitor center with a little shop, and a charming tearoom in the castle. You can also go on ranger-led walks of the park for €10. Cars must be parked at the visitor center, but a shuttle bus can take you up to the castle for €3 round-trip (€2 seniors, students, and children).