The Three Counties cave system is the longest and most complicated system in Britain - it is currently thought to be around 89km long with over 40 different entrances. It is possible to go underground in Yorkshire, pass under Lancashire and emerge in Cumbria. The different parts of the system have different names which tell a story in themselves: Wretched Rabbit passage, Lancaster Hole, Bull Pot of the Witches, Pipikin and Link to name a few.
Its numerous entrances means that a variety of through trips are possible. The main Ease Gill stream way is regarded as one of the finest in the UK. There is also a complex of high level fossil routes which now always remain dry.
The system continues to grow as new links are made. If a connection is made to the Kingsdale system then it will become the first cave system in the UK to be more than 100km long.