The Three Sisters (5L13)

Site Description:

The cave known as The Three Sisters has been recognized in the Mount Gambier region since at least 1933, when it was first documented by scientist and explorer Norman B. Tindale. Originally, the cave featured three roof-window openings leading into the cavern below. However, today only one accessible entrance remains— a gated opening located a few meters west of the bitumen-paved Glencoe Mile Hill Road, near Tantanoola.

Access to the cave is through a 1-meter diameter concrete pipe, which leads to an 18-meter vertical drop. At the base of the drop lies a large talus mound. From this point, the cave slopes steeply downward in all directions from the apex of the mound.

Visitors should exercise caution due to the presence of numerous glass fragments and other debris scattered across the 30-meter diameter dome chamber.

Several speleothems are prominently visible within the cave, and numerous tree roots are visible hanging from the surface above.

The fixed line begins on the right-hand side of the lake and descends rapidly to a narrow restriction, characterized by a smooth, 30-40 cm high "flattener" that extends for several meters. Beyond this restriction, divers enter the upper section of a large, roughly circular chamber, which slopes downward to the right and is scattered with sizable slabs of white limestone. The current known depth of the chamber is approximately 35 meters.

Site Access Requirements:

• Hold a minimum of  Advanced Cave rating.
• Have the skills and fitness to climb a 18-meter free-hanging wire rope ladder. If unable to do this, divers must contact the Site Access Officer at least 1 week prior to discuss ingress/egress options.
• Once booking has been confirmed, a key for this site is available for collection at the Glencoe Post Office and Bistro, which is open 9AM to 5 PM daily.

Site Specific Requirements:

• Only one vehicle to be parked on the hard pan area near the cave entrance at any given time. All other vehicles to be parked away from the cave entrance, on the fire track behind the cave (see map).
• At no time are divers to park on the opposite side of Mile Hill Road in order to access the site. This is against the lease agreement and will cause cave access to be removed.
• One responsible adult must remain topside at all times.
• High visibility clothing and traffic cones to be used around cave entrance. 
• All persons to be connected to a belay prior to approaching cave entrance
• Helmets to be worn whilst inside the cave
• Maximum of 4 divers in the water at any one