Caves and tunnels have always been part of human life. We've grown more adept at shaping these underground shelters and passages over the millennia, and today we dig for hundreds of reasons. We excavate to find both literal and cultural treasures, digging mines and unearthing archaeological discoveries. We use caverns for stable storage, for entertainment, and for an effective shelter from natural and man-made disasters. And as the planet's surface becomes ever more crowded, and national borders are closed, tunnels provide pathways for our vehicles and for smugglers of every kind. Collected below are some recent subterranean scenes from around the world. Israeli Antiquity Authority archeologist Annete Nagar shows the 2,000-year-old Second Temple period drainage tunnel under Jerusalem's Old City at the west side of the Jewish Wailing Wall on January 25, 2011. Israeli archaeologists have finished work, which started in 2004, on the tunnel that starts at a site near the flashpoint Al-Aqsa mosque compound inside the walls of Jerusalem's Old City, officials said. Tourists visit the Kuha Karuhas pavilion located inside the Phraya Nakhon cave, in the Khao Sam Roi Yot national park, some 300 km south of Bangkok, Thailand, on December 5, 2010. The pavillon was built in 1890 on the occasion of a visit to the cave by King Chulalongkorn, the grand-father of current King Bhumibol Adulyadej. A miner stands in front of a giant drill machine after it broke through at the final section Sedrun-Faido, at the construction site of the NEAT Gotthard Base Tunnel March 23, 2011. The project consists of two parallel single track tunnels, each of a length of 57 km (35 miles).