Architecture, a massive work formed of large stones laid in the sea by means of coffer-dams, extended either in a right line or an arc of a circle, before a port, which it serves to close; to defend the vessels in port from the impetuosity of the waves, and to prevent the passage of ships without leave. It is frequently fortified.

Mole (mole), amongst the Romans, was also used for a kind of mausoleum, built in the manner of a round tower on a square base, insulated, encompassed with columns, and covered with a dome. The mole of the Emperor Hadrian, now the castle of St. Angelo, was the greatest and most stately of all the moles. It was crowned with a brazen pine-apple; in which was a golden urn containing the ashes of the emperor.