Now here is something completely different, and quite unique.
Caves don’t necessarily need to be in limestone. We are blessed in Victoria to have caves set in Limestone, Granite, and also Basalt (Volcanic). The Western part of Victoria is one of the largest Basalt plains in the world. These lava tubes are quite rare compared to limestone and visiting cavers should definitely have a look!
Quite a few of the volcanic caves are immense and could park jumbo jets, but don’t go far or even really have a dark zone. But the size is still impressive. We take our lava caves a bit for granted in Victoria which is a shame as they are nowhere near as common as limestone caves.
A word of advice – Lava tubes eat your light and your clothes! Volcanic caves are peculiar compared to Limestone caves in several ways worth noting. Firstly, they are really sharp. Cotton Overalls will only last one weekend in this environment – they get shredded to bits. I would not suggest wearing an expensive cave suit into these caves as they even destroy tough fabrics such as Cordura.
Also, Volcanic Caves eat up your light. Due to the colour of the rock (often brown or black) your torch light Is absorbed and will seem less bright. There are types of decoration specific to Basalt caves, including stalactite type formations and sometimes crystals.
The Byaduk lava caves are extremely young geologically, being only around 8000 years which is nothing compared to everything in Victorian limestone. It is also said that they are amongst the easiest lava caves to access in Australia. All of these caves are easy and rating one, apart from those with gear needed for entrance.
The volcanics are not my area of speciality, but here are the highlights. In the Skipton / Mt. Hamilton and Mt. Fyans area there are just a few caves of note:
Mt Hamilton Cave – H2
This is a complex and interesting cave on a number of vertical levels approximately 1.2km long. I’d say this is probably the best volcanic cave in Victoria in terms of its length and complexity. The cave actually looks and feels (and even smells) like a limestone cave, and there are a couple of hours’ worth of exploration possible to see the whole thing. All easy and totally suitable for beginners.
The entry to the cave is by a short permanent ladder, in a discreet vertical entrance in a paddock. Some interesting features including the beehive chamber, which is a perfect dome with hive like indentations in the walls. Until relatively recently the Mt. Hamilton lava tubes described were some of the longest in Australia, but longer tubes have been found in Queensland.
Mt. Hamilton Cave is on private property and there are two other volcanic caves adjacent, which are Sausage Cave and Insect Cave, but both are less than 50m each surveyed length. The three together make a good day of exploring. VSA have had trips to these caves in the past and the landowner has been known to the club, although no trips have happened for many years.
Skipton Cave (Mount Widderin) – H1
Basically two chambers connected by a small arch, with some upper level passage. This cave was a bat colony many years in the past. Cave is about 240 metres surveyed length.
In the Budj Bim (Mt. Eccles) area there are more caves of note:
The Shaft – H8
This is the open vent of a small volcano. The cave is essentially a single large elongated chamber, but what makes this interesting is you need a 23m ladder or SRT to access the cave. Rigging is a bit tricky with 20m of slings needed to tie back to a boulder as anchor, as to avoid delicate fauna. There are some lava stalactites to see in this cave.
Tunnel Cave – H9
This cave is a standard lava feeder tube of about 60m which has been compared to a railway tunnel in size and shape. Some lava drips are to be seen here, with a gradually lowering roof.
Natural Bridge (Gothic Cave) – H10
A short 36m of cave. Not much to it. The cave has an angular arched roof which gave it its other name, Gothic Cave.
North Pole Cave – H51
This cave is a big longer and more sporty, with some squeezes and tubes. It is also a lot longer than those described above, and there are some good lava features to see. There are some interesting tree roots coming through to see also. This one is worth doing if you are in the area.
Pudding Cave – H53 and H76
This cave is 160m surveyed length, and has two entrances. Some interesting crawls and lava formations, with low chambers and passages.
Footes Cave – H54
A large entrance chamber which connects to a short tunnel and flattener over two levels. Not much else to this cave.
Carmichael Cave – H70, H71, H79
Another more interesting and complex cave at 605m surveyed length. Many small tunnels alternating with low broad chambers, with a lower level at the far end coming to a larger and partly collapsed chamber. Many good lava formations with interconnected levels. Another volcanic cave that is one of the best in the area.
The other popular volcanic area is the Byaduk Caves, with a lava flow that came from Mount Napier. There are a few more caves of note here:
Harman Caves – H11, H12
Two caves with a connection that is tricky to find, with a tight squeeze through rubble needing to be negotiated. Harman 1 is mostly large passage with a rubble floor, and Harman 2 consists mostly of a large chamber ending in a lava wall. Some interesting lava bursts and drips to be seen.
Bridge Cave (And dolines) – H13 and 14D
A handline is suggested to enter on the South wall of the western doline. This is a pair of large collapsed dolines, with a complexly branched lava tube system with more short passages at the east and west ends. Again, some interesting lava drips to be seen.
Church Cave – H15
This cave is a bat shelter in Winter so please do not enter at that time. Multi level system similar to the Harman caves, but a bit larger.
Church Arch – H16
A spectacular arch connecting two long sections of collapsed tunnel. Tunnel is about 12m high, 25m wide and 60m, so it’s pretty large.
The Turk – H24
An entrance chamber with some lava lining on the southern wall. Another short crawl leads to the inner chamber with well preserved features. The walls and ceilings have lava drips and other volcanic decoration.
Staircase Cave – H25
A single larch chamber with a series of lava benches that are like a staircase, with a lot of volcanic decoration.
The Theatre – H33
This is the most interesting and complex cave at Byaduk. A short ladder or handline is recommended for the first drop, and a 10m ladder or SRT for the second drop. There is a connection to H25 but the rockpile is unstable and the connection is definitely not encouraged. This cave has multiple levels with several descending chambers connected by lava cascades. The theatre chamber is at the very bottom.
Chocolate Surprise – H74, H106, H108
General low and crawly and sharp caves, with SRT or ladders needed to reach the separate cliff entrances. Basically three different caves stacked on top of each other without open connections of their levels. Some good lava formations in all three caves.
Turtle Cave – H90 and H91
Small cave that looks like a turtle shell beside the track on the way to Harman 1. This is a lava blister. Some good lava drips to be seen on the ceiling.
The other volcanic cave worth mentioning is: Parwan Cave.
This cave is very close to Melbourne, but is not done often as it is on private property, south of Bacchus Marsh. The cave is a classic example of a lava tube. The cave is quite long for its type, listed in the Karst Index as being about 300m in length. The landowner is generally friendly to cavers, but permission must be sought. As a day trip I would recommend Parwan over the granite caves mentioned above.
None of these are extensive in the same way our limestone caves are, but they make a refreshing change and something a bit different to explore. Suffice to say that there are lots of options in the volcanic areas, and they are sadly very much overlooked by Victorian cavers. The caves are generally easy, with a few opportunities for laddering or SRT. The nearby campgrounds make accommodation easy.