Republic of China (Taiwan) - The 700-m (2,296-ft) Beihai Tunnel runs from the Tieban coast into channels carved underneath Nangan. Pleasure boat rides ply its crystal-clear waters.
India - Glowing under warm illumination, the Revoli Tunnel at Lower Bazaar is an underground passageway located in the heart of Shimla, a bustling city in the country's Himachal Pradesh state.
Vietnam - Not for the claustrophobic, the Cu Chi tunnel complex in Ho Chi Minh City offers a fascinating glimpse into the way Viet Cong forces operated below ground during the Vietnam War.
