Precinct Features include a series of volcanic systems that link a number of major cones with the ocean via extensive lava flows.
Byaduk Caves (27)
The Byaduk Caves in Mt Napier State Park are the most extensive and accessible set of lava caves in Australia. Being so young (only 8,000 years), they are largely unweathered and in their natural state. They were formed when a spectacular lava fountain several hundred metres high roared up from a lava lake in Mt Napier’s crater approximately 8,000 years ago. The lava rose from a depth of over 30km and its temperature was about 1200 degrees Celsius. It flowed in four directions, and the westerly flow, down Harman’s Valley, extends for approximately 24km. The caves are accessed through collapsed roof sections and display many well-preserved features left by the retreating and cooling lava. The largest tunnels are up to 18 metres wide, 10 metres high, and extend to depths of 20 metres below the surface.
Near the limits of the Harmans Valley flow at Wallacedale, 13 kilometres west of the Byaduk Caves, are a number of unusual clusters known as lava tumuli. The tumuli are circular mounds or hummocks of rock up to 10 metres high and 20 metres in diameter, and are considered to be not only unique in Australia, but most likely rare on a world scale. When the surface of a lava flow quickly crusts over, pressure in the liquid lava beneath can cause the crust to rise. Generally, it forms irregular broad mounds and hollows known as Stony Rises, but occasionally, it creates smaller, steep-sided domes called tumuli.
Mount Rouse (29B)
Mount Rouse is a massive accumulation of scoria, rising 100 metres above the surrounding volcanic plain. It is the highest relief in the area and is an important vantage point to view the lavas and adjacent volcanoes of Mount Eccles and Mount Napier. To the south of the main scoria cone is a deep circular crater with a small lake and a smaller shallow crater rimmed with basalt. Past lava flows from Mt Rouse followed shallow, gently sloping river courses, extending at least 60 kilometres south. A thin basalt lava flow contained in the scoria cone has been dated at approximately 1.8 million years old. If this is accurate, then Mount Rouse marks the beginning of the second (younger) phase of activity in the Newer Volcanics Province.
Mount Eccles/Budj Bim Lava Flow/Lake Condah (30, 31, 32)
More than 30,000 years ago the ground around “Budj Bim” today also known as Mount Eccles, erupted and rumbled with lava flows branching out to the west and being distributed along canal to the surrounding area. Large wetlands were created from these lava flows to an area known as Lake Condah where the local Gunditjmara people harvested eels and fish. They used the stones of the lava flow to construct elaborate channels, weirs , fish-traps , wind breaks and stone huts. Tours can be arranged through the Winda Mara Aboriginal Corporation in Heywood. It is an area of local and national significance as it is considered to be Australia’s earliest and largest aquaculture venture and the only place in Australia where Koori people built permanent stone houses.
The Bunj Bim National Heritage Landscape was Heritage Listed in 2004.
Tower Hill and Interpretation Centre (34)
Tower Hill Game Reserve is located 15 kilometres west of Warrnambool features a deep circular crater which is believed to have formed some 25,000 years ago and is one of the largest maars in the world.
Lady Julia Percy Island (33)
Lady Julia Percy Island, located just off the coast of Port Fairy, is a low, flat island built of submarine basalt flows up to 7.8 million years old. Ringed by cliffs, with a flat treeless top, the island is 2 km long and 1 km wide at the southwestern end, with a plateau surface averaging 30 to 40 metres above sea level.
This is the only major basalt island off the western Victorian coast, and although not readily accessible, the volcanic sequence is unusual and clearly exposed.
While the Island is home to mutton-bird colonies, fairy penguins, lizards, sea birds, crayfish and sharks, it is seals, which clearly dominate. Parks Victoria has counted 23,000 seals, making it the largest colony of Australian fur seals in the southern hemisphere.
The seals swim about 30 kilometres to feed on squid along the edge of the undersea continental shelf for a week at a time before returning to the island to digest, or feed their young or sun themselves.
Hopkins Falls (35)
The Hopkins River pours over a beautiful basalt escarpment at Wangoom. In winter and spring the viewing is spectacular and for a couple of weeks in late summer it is sometimes possible to see baby eels (elvers) climbing the falls. Toilets, BBQ and picnic facilities are available.