The possibility of connecting a number of discrete cave systems in the area to create a single super-system that spans the county borders was first proposed by Dave Brook in 1968, and it was achieved in 2011.

[6] The Three Counties System contains a number of major subterranean streams, all of which combine to resurge at Leck Beck Head above Cowan Bridge.

Some of the system is believed to pre-date the Anglian stage which started at about 478 ka,[8] with one stalagmite in Lancaster Hole being dated to over 350,000 years old, whilst other sections are still being formed today.

[10] The Leck Beck Catchment Area Site of Special Scientific Interest, which is based around the catchment area of the Three Counties System, states in its reason for notification: "The scale and variety of the caves makes this a most important site for the study of surface and underground landform development over a long period of the recent past.

To the north in Barbondale, Aygill Caverns is known to drain into Bull Pot of the Witches, but a route through the underwater passages has yet to be negotiated.

[59] Further north still, a major abandoned route in Aygill Caverns, known as New Year Passage, heads up the Barbondale valley, and may connect with other known caves.

[61] Marble Steps, a major active system with large fossil fragments, could well be connected to Rift Pot.