Caving
"Portsdown Tunnels - Researching the sites of, Acclimbatize, AGC UE, Andy Sparrow - Caving Services, Andy's Caving Site, BCRA - Events Diary, Cave And Mine Photography, Caves & Caving, Caves and Caving in the UK, Caving Routes in the Yorkshire Dales
Adventure Unlimited
Charity offering a range of outdoor pursuits for young people and adults. Regular clients include schools, youth groups, companies and individuals.