Secret cities lay hidden in the intimidating Himalayas, the perilous passes to them known to only a few. Fierce monsters were said to lurk in the swamps of north-east India. The mighty River Brahmaputra flowed through Assam and Bengal, but its place of origin was a big mystery. And in the cold, windy deserts of Central Asia, the fastest horse on earth galloped wild. Yet, intrepid explorers ? men and women ? full of curiosity and thirsty for knowledge, travelled to these distant and forbidding places. They returned with extraordinary tales and important discoveries, forever leaving their mark on history.