Three Mile Beach is a coastal beach located within the Westland Tai Poutini National Park on the West Coast of New Zealand's South Island. It is a sandy beach situated within Big Bay, also known as Awarua Bay, which is a large, roughly square indentation in the coastline. The Awarua River enters the bay at the northern end of this beach. Access to the beach is remote and requires planning. One documented approach involves reaching the Kongahu coast via a shingle road off the main highway near the Mokihinui River, then either walking a cattle track over Gentle Annie headland or, at low tide, scrambling around Gentle Annie Point rocks to reach Three Mile Beach. The beach's name historically denoted its distance, three miles, from the Mokihinui River. The coastal route south from here involves beach walking with occasional headlands, passable only at mid to low tide. The surf conditions have been historically noted as hazardous, with a government survey in the 1860s reporting a drowning in the surf. The area is exposed to the Tasman Sea, and paddlers must be acutely aware of tide tables to navigate the rocky points and river mouths safely. The beach is backed by active coastal dunes. There are no dedicated boat launch facilities, amenities, or specific regulations for paddlers at this remote location. The area has historical significance from the West Coast gold rush era, when a small settlement was expanded here.