Giant's Causeway in Northern Ireland.
Giant's Causeway definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
headland in N Northern Ireland, consisting of thousands of small, vertical basaltic columns: c. 3 mi (4.8 km) long
Giant's Causeway definition by American Heritage Dictionary
A basaltic formation on the northern coast of Northern Ireland. It consists of thousands of columns of volcanic origin forming three natural platforms. According to legend, it was once a bridge for giants crossing between Ireland and Scotland.