"April 12th.- In the morning we stood out of the lagoon on our passage to the Isle of France. I am glad we have visited these islands: such formations surely rank high amongst the wonderful objects of this world. Captain Fitz Roy found no bottom with a line 7200 feet in length, at a distance of only 2200 yards from shore; hence this island forms a lofty submarine mountain, with sides steeper than those of the most abrupt volcanic cone. The saucer-shaped summit is nearly ten mile across; and every single atom, from the least particle to the largest fragment of rock, in this great pile, which however is small compared with very many other lagoon islands, bears the stamp of having been subjected to organic arrangement... This is a wonder which does not at first strike the eye of the body, but, after reflection, the eye of reason." Charles Darwin, Voyage of the Beagle
I will agree. It is truly amazing. The tiniest (well, very tiny) of creatures build some of the largest structures. I can't even picture these dimensions in my head and the time spans involved are just as amazing.