Islay resident Katie Featherstone takes readers on a long and rugged walk to discover both the wild nature and the harsh human history of the Oa peninsula. A curiously round protrusion, the Oa forms the most southerly part of Islay. Far from the gentle hills and long sandy beaches for which the rest of the island is known, this peninsula towers above the sea with eroding, rocky cliffs, dramatic sea stacks, and hidden coves. With half the landmass run by the RSPB as a nature reserve, it’s known for its birdlife, particularly choughs, hen harriers, and nesting golden eagles. Only…