Peruvian surfer Domingo Pianezzi rides a wave with his alpaca, Pisco, at San Bartolo beach in Lima, Peru, on March 16. Pianezzi has spent a decade training dogs to ride on the nose of his board, and now he is the first to do so with an alpaca. Pilar Olivares/Reuters
A Thai riot soldier wears a gas mask at the Government House in Bangkok, Thailand, on March 16. Tens of thousands of protesters pressed ahead with a mass rally in Bangkok on Tuesday, some expressing frustration that four days of peaceful protests had failed to force Thailand's premier to call elections. Leaders of the 'red shirts' collected blood from supporters which they spilled outside the gates in what they are calling a symbolic sacrifice for democracy. Chaiwat Subprasom/Reuters
Convention visitors watch a 3-D movie presentation during the ShoWest 2010 State of the Industry Update in Las Vegas on Tuesday. Matt Sayles/AP
A woman walks along the Persian Gulf in Muharraq, Bahrain, on March 16, during the sunset. Hasa Jamali/AP
A Palestinian protester picks up a tear gas canister fired by Israeli border police during clashes in the East Jerusalem neighborhood of Issawiya. Dozens of Palestinians clashed with Israeli police on Tuesday. Darren Whiteside/Reuters
Victoria Azarenka of Belarus sits with a towel over her head during a changeover during her match against Maria Jose Martinez-Sanchez of Spain at the Indian Wells WTA Tennis Tournament in Indian Wells, Calif., on Monday. Martinez-Sanchez defeated Azarenka in the match. Danny Moloshok/Reuters
First Lady Michelle Obama continues her campaign to improve fitness and combat childhood obesity at an appearance at the Grocery Manufacturers Association Science Forum meeting in Washington on March 16. J. Scott Applewhite/AP
A CodePink protester holds up a sign during a Senate Armed Services Committee hearing on Capitol Hill in Washington, March 16. Harry Hamburg/AP
A tourist lies on the grass surrounded by spring flowers in central London on March 16. Stefan Wermuth/Reuters
Riders compete in the Arkle Challenge Trophy during The Festival at Cheltenham Racecourse on March 16. Russeel Cheyne/Reuters
People ride a roller coaster during a media preview at Universal Studios Singapore on March 16. Wong Maye-E/AP
A Bali resident watches the sunset on Kuta Beach, Indonesia, during Silence Day on Tuesday. Hindus in the world's most populous Muslim country celebrate their new year by observing a day of silence, in which they have to stay inside their homes and meditate in silence and darkness for the entire day. Firdia Lisnawati/AP
The government intends to combine three separate regions of Sanjiangyuan to create China’s first national park, setting aside an area the size of Pennsylvania. China is also working to set up a series of other trial national parks around the country.
More than 2,700 miles before the Mekong River drains into the South China Sea, before it winds past the ancient Khmer temple of Vat Phou and the poppy fields of the Golden Triangle, it begins on the Tibetan Plateau in western China. Tibetan Buddhists believe the spiritual source of the river is an alpine lake called Zaxiqiwa. Scientists have argued for decades over the river’s geographical origin. Not one of them doubts that it trickles down from a glacier high in the serrated mountains. The question is which one.