Caving
From Tardis Wiki, the free Doctor Who reference
Caving was not among Bratheen Traloor's hobbies and he did not do it on Rhinvil in part because House would be unable to assist him if he had an accident. (AUDIO: Professor Bernice Summerfield and the Stone's Lament [+]Loading...["Professor Bernice Summerfield and the Stone's Lament (audio story)"])