Plas Tan y Bwlch is the old Oakeley estate house above the Vale of Ffestiniog, near Maentwrog, its wealth built on the slate quarries at Blaenau Ffestiniog. The nineteenth-century gardens climb the hillside in terraces, thick with rhododendrons and specimen trees, with woodland paths and long views down the valley. Grade II* listed. For years the national park’s environmental study centre; the grounds are open to walk.

© Mark Percy / Geograph · CC BY-SA 2.0