Port Alberni is a deep-water port located in the south-central midriff of Vancouver Island.
Despite its heartland location, tidal waters flow right to the foot of town from the open Pacific Ocean via Barkley Sound (south of Ucluelet) and the narrow finger of salt water known as the Alberni Inlet. Essentially a long fjord, the inlet is also known as the Port Alberni Harbour and stretches for 40km/25mi down a lean passage of forested west coast terrain.
Nestled at the foot of the Vancouver Island Ranges, Port Alberni is shadowed to the east by Mount Arrowsmith, which at 1,819m/5,967ft is the highest peak on the island's southern half. The Alberni Valley was carved out by glacial activity and the oldest rocks in the area date from the Middle Devonian period approximately 400 million years ago. Limestone karst formations are commonplace here as in other parts of the island, and the caving is particularly good in the Sproat Lake area.