the.com/reefs
Cities built by animals too small to know they're architects.
means Underwater ridges built from the limestone skeletons of coral colonies, teeming with marine life.
from From the Old Norse rif, a ridge or rib, originally any hidden ledge that wrecked ships before it dazzled divers.
Tiny buildersEach polyp is smaller than a pencil eraser.
Ocean nurseriesQuarter of marine species live among reefs.
AncientThe Great Barrier Reef predates human civilization vastly.
Living rockWhat looks like stone is animal skeleton stacked.