Members of the Penan tribe of northeastern Borneo know that Batu Lawi, a 2,000-m sheer limestone pinnacle, is a demon-haunted place to be avoided at all costs. To Bruno Manser, however, Batu Lawi represented everything he loved about the untouched forest of the region. He almost perished trying to reach its summit in 1988. As he told friends, he spent 24 hours hanging from a rope, unable to reach the rock face. Only a desperate swing brought him within grabbing distance of the rock.
Fourteen months ago, Manser returned to Batu Lawi at the end of a 12-year...