Wilsons Promontory forms the southernmost tip of mainland Australia, where 50,000 hectares of granite massif, heathland, and eucalypt forest terminate at a fractal coastline of sheltered bays, sea caves, and exposed headlands. The peninsula's granite outcrops—some rising 700 metres above Bass Strait—were shaped by tectonic uplift and marine erosion over 400 million years. Aboriginal Gunaikurnai and Bunurong peoples occupied the region for at least 6,500 years before European arrival; shell middens and stone tool sites remain visible along tidal flats. The promontory was mapped by George Bass in 1798 and later named for Thomas Wilson, a London merchant who sponsored early Pacific exploration. By the 1870s, grazing leases and lime kilns dotted the peninsula; in 1905, Victoria gazetted the area as a national park, one of the state's first, though grazing continued until the 1960s. Today Wilsons Promontory National Park receives over 400,000 visitors annually. The coastline supports colonies of Australian fur seals, little penguins, and short-tailed shearwaters; southern right and humpback whales migrate through Bass Strait between May and October, often visible from headland lookouts and from the water. The marine environment includes kelp forests, sponge gardens, and subtidal granite reefs that extend to 40 metres depth. Tidal River, the park's primary visitor hub, operates year-round with a Parks Victoria information centre, accommodation, and marked walking trails radiating to Squeaky Beach, Oberon Bay, and Mount Oberon's summit lookout. The park's remoteness—240 kilometres southeast of Melbourne—preserves a sense of isolation rare in southern Victoria. Wilsons Promontory full day cruise options navigate sections of the park's 130-kilometre coastline otherwise inaccessible to day walkers. Vessels typically depart from Tidal River or Port Welshpool, tracing granite cliffs, crossing Waterloo Bay, and rounding the lighthouse reserve at South Point. Afternoon wilderness tours focus on shorter coastal loops, while whale migration cruises follow seasonal humpback and southern right whale movements through deeper channels. On-board interpretation covers geological history, Aboriginal connection, and marine ecology. Lunch is provided on extended departures. The coastline's exposure to Bass Strait weather means sea conditions vary; cancellations occur during high winds or swell. Booking a Wilsons Promontory full day cruise tour in advance is standard practice, particularly during spring wildflower season and the winter whale window.