The most severe drought in 70 years of record keeping threatens the Horn of Africa with famine.

Many of the canals and floating fields used by ancient civilizations in the Valley of Mexico were lost as lakes were drained, but some examples of the watery fields remain in Xochimilco.

A small research station in Hawaii where analog astronauts simulate living and working on the Moon or Mars is out of harm's way after a lava flow appeared to be headed in its direction.

The park is one of the most isolated natural areas in the continental United States and the site of long-running ecological studies.

The quiet Caribbean island has been a destination for divers looking to spot corals and sea urchins.

Saharan dust clouded the skies but stayed low enough to frame the Italian island's famously active volcano.

Three consecutive years of La Niña conditions in the eastern Pacific Ocean make this a rare “triple dip” event.