The most extensive caving area in the south-west is the Witchcliffe area, stretching from south of Calgardup Brook to the Boranup Sand Patch. This sector contains over 135 speleological features of which 40 are major caves. The camp sites of the two main caving groups can be found in the Boranup area of this section. From these sites most of the caving activities are conducted. A good proportion of the stream caves are to be found in the northern part of this area. The best example of these is the Mammoth Chain, consisting of three large cave systems formed by the same stream but separated only by the collapse of limestone. Mammoth Cave is the inflow and is also a tourist cave. It is followed by Terry Cave, then Conference Cave. Another chain of caves, slightly to the north is believed to be where once the stream flowed and could possibly be an older stream system. Terry Cave is the only cave in this system which requires equipment, that is, a 15 m ladder and rope to descend the main entrance pitch. The other caves in this area are also well worth a visit and require no equipment but a guide is needed to locate them.
A little over 1 km to the north of Mammoth Cave is Calgardup Cave which used to be an old tourist cave. From here one can take the Bobs Hollow track to the beach (4 WD is advised) to see Bob's Hollow Cave, the only example so far known, of an efflux cave to be found in close proximity to the sea. Inland from Bob's Hollow is Connolly's Cave, this being the longest known stream cave in the Witchcliffe area. It is an excellent sporting cave consisting of over 2 km of passageway. There are vertical squeezes and also a number of good mud crawls to be found. It requires more than six hours to see this system properly. A guide is required to find this cave and a 12 m ladder is needed to descend the entrance pitch.
South of Mammoth Cave are Lake, Bride, Giant's and Golgotha Caves. Bride Cave is a large doline approximately 100 m across. This is a good cave for SRT fanatics and has a pitch on the deep side of over 50 m with a cave at the bottom. These caves are easily found from Caves Road. Golgotha Cave is 1 km south of Bride Cave on Caves Road. Also in this area are several other caves of interest.
Eight kms south of these caves is the Boranup Camp Site. Very little is known about the area between Golgotha and the campsite as only one large cave has been found, namely Green Cave, and several fissure caves found in the seventies near Blue Rock Road. They are believed to be formed by the acyion of water from a swamp opposite, undermining the limestone causing it to collapse forward in large blocks, forming deep fissures in the limestone.
From the Boranup campsite, many fine caves can be visited as some are within a short walking distance from the campsite. These are Dingo, Nannup, Mill, Strong's, Crystal, Arumvale Caves and Arumvale Pipe plus numerous smaller caves and karst features. Strong's is the finest stream cave in the area.