National

The Asian tsunami of 2004 killed more than 170,000 people in the Indonesian province of Aceh alone, washing away tens of thousands of homes, schools and businesses. Two years later, reconstruction is under way, but serious challenges in housing and infrastructure remain.

It took them two years, but Colin Angus and Julie Wafaei are the first people to circumnavigate the globe completely by self-propulsion. That means they rowed across the Atlantic -- no sails. And biked and hiked across Siberia.

It took them two years, but Colin Angus and Julie Wafaei are the first people to circumnavigate the globe completely by self-propulsion. That means they rowed across the Atlantic -- no sails. And biked and hiked across Siberia.

In literature, albatrosses represent weighty, inescapable burdens. But in real life, the huge seabirds use wind energy to cruise around the planet's oceans. Photographer Frans Lanting and writer Carl Safina report from one of the world's largest albatross colonies.

In literature, albatrosses represent weighty, inescapable burdens. But in real life, the huge seabirds use wind energy to cruise around the planet's oceans. Photographer Frans Lanting and writer Carl Safina report from one of the world's largest albatross colonies.

Running underneath the rolling hills of Tennessee lies a still-mysterious and remote network of caverns. Many of those caves shelter fragile ecosystems, and biologist Jerry Lewis is helping to discover and protect some of those ecosystems from man's destruction.

Running underneath the rolling hills of Tennessee lies a still-mysterious and remote network of caverns. Many of those caves shelter fragile ecosystems, and biologist Jerry Lewis is helping to discover and protect some of those ecosystems from man's destruction.

North Korea's active military is one of the largest in the world at 1.2 million men. The troops are backed up by a significant missile arsenal that can hit targets in South Korea, and Japan.

Mingma Norbu Sherpa was one of 24 conservationists killed in Nepal this week in a recent helicopter crash near Kathmandu. A child of the Himalayas, Sherpa, 50, was an official with the World Wildlife Fund who helped change conservation practices around the world.

Mingma Norbu Sherpa was one of 24 conservationists killed in Nepal this week in a recent helicopter crash near Kathmandu. A child of the Himalayas, Sherpa, 50, was an official with the World Wildlife Fund who helped change conservation practices around the world.