Los Teñideros--A Chemical Reaction Where Two Rivers Meet

(Photo: José David Leiva)

Two streams in Tenorio Volcano National Park in Costa Rica merge to form the Rio Celeste. One of them has large quantities of sulfur and calcium carbonate, which gives the river a beautiful blue tint. There is a remarkably sharp dividing line when these two streams merge that is known as Los Teñideros, which means "the dyers."

-via The Soul Is Bone