History of the Peloponnesian War

And falling in hand with the work, they performed it, not with iron tools to hew stone, but picked out such stones as they thought good and afterwards placed them as they would severally fit. And for mortar, where it was needed, for want of vessels they carried it on their backs, with their bodies inclining forward so as it might best lie, and their hands clasped behind to stay it from falling, making all possible haste to prevent the Lacedaemonians and to finish the most assailable parts before they came to succour it.

For the greatest part of the place was strong by nature and needed no fortifying at all.