http://www.viewzone.com/sender.html
more pics on this link, fascinating, like certain spherical boulders, the 'bricks' are hollow and filled with sand...similar have been discovered in Australia but I lost the link...
The legendary explanation for the Giant's Causeway (which runs from Ireland to Scotland, but almost all of it underwater) is that a giant (I forget, probably Finn / Fingal) built it to get at some foe in Scotland. :')