Latitude -35.349191, Longitude 150.265117
Located in the Shoalhaven Region of NSW, nearest town Ulladulla
Source: Geological Survey of NSW, Ulladulla 1:250,000 Explanatory Notes, G. Rose
Pigeon House Mountain was named by Lieutenant James Cook (later Captain) during his voyage along Australia's eastern coast in 1770. At 720m above sea level, the prominent remnant of Pigeon House's two tier sandstone structure dominates the landscape. The local aboriginal tribe called it Didthul, a word meaning "woman's breast", due to the similar shape, and now it is known as Pigeon House Mountain/Didthul.
Many people incorrectly assume that Pigeon House Mountain/Didthul is a volcanic plug; in fact it is sedimentary in origin, laid down in a marine environment during the Permian age, 260mya when Australia was close to Antarctica. It is located on the southern portion of the Sydney Basin.
The rocky crown of the mountain consists of Nowra Sandstone, a member of the Shoalhaven Group. It is a cap of hard sandstone, resistant to weathering and overlays Wandrawandian Siltstone, which is above the harder sandstone of the Snapper Point Formation, forming the lower cliff line. The Permian sediments overlie much older and tightly folded rocks of the coastal hinterland to the south. These are Devonian, Silurian and Ordovician sediments of quartzite, phyllite, sandstone and shale.
The return walk to the top of Pigeon House Mountain/Didthul takes about 4 hours. It is best tackled in the cooler months but always remember to take plenty of water and light protective clothing in case of a weather change. The walk begins with a steep climb of 800m from the car park to the first cliff line then the track follows a steep spur through a forest. The rock types of this section are metamorphosed Ordovician sediments that are about 490 myo. The first sandstone cliff line is early Permian, which is about 250 myo. Continue on a flat walk of 1km from the top of the first cliff line to where the sandy track starts to climb again.
A steep climb of 500m leads to the base of the ladders and the cap of Nowra Sandstone. The summit of Pigeon House Mountain/Didthul is reached by climbing steel ladders attached to the cliff face.
From the top of Pigeon House Mountain/Didthul there are extensive views over Morton National Park and you can see where the very flat plateau has been dissected by deep gorges. This plateau is known as the Yalwal Ramp and dips gently to the north-east, where it passes under the Nepean Ramp and younger coastal sediments. Cliffs developed in the harder rocks and formed the gorge rim.
Contoured weathering of horizontal rock on the plateau gives a terraced appearance. Small outcrops of Tertiary basalt occur on the plateau-top and valley floors throughout the western part of the Yalwal Ramp.
Pigeon House Mountain/Didthul is easily accessed from Ulladulla. Drive south on the Princes Highway and turn off to the right/west into Wheelbarrow Road, then left into Woodburn Road, right into Clyde Ridge Road, then right into Yadboro Road. You will see a sign to the car park which is on the right (northern) side of the road.