Unexplored Forest. The Helios Grove in Redwood National Park, discovered in 2006. The grove may not have been visited by humans in thirty years, and no one understood that it contains the world's second- and third-tallest trees, Helios and Icarus. Left to right: Ruskin K. Hartley (Director of Save-the-Redwoods League [SRL]); Marie Antoine; Kenya Lewis of SRL; Dorinda Nyberg of SRL; Jim Spickler (in white cap). Photo by Richard Preston, © Richard Preston.