From vibrant Old San Juan to lush El Yunque National Forest, here are all the must-sees and -dos on a quick trip to the ...

A single mature, leafy tree is estimated to produce a day's supply of oxygen for anywhere from two to 10 people. Phytoplankton in the ocean are more prolific, providing half of Earth's oxygen ...

With a gilt-edged southern coast, a capital city sculpted by conquests, and a dramatic interior that sets the heart racing ...

We tested an active hyperspectral LiDAR instrument in a laboratory measurement of spruce and pine trees to find out whether these species could be separated by means of combined range and reflectance ...