Тестаччо
Amphorae are of great use to maritime archaeologists, as they often indicate the age of a shipwreck and the geographic origin of the cargo. They are occasionally so well preserved that the original content is still present, providing information on foodstuffs and mercantile systems. Amphorae were too cheap and plentiful to return to their origin-point and so, when empty, they were broken up at their destination. At a breakage site in Rome, Testaccio, close to the Tiber, the fragments, later wetted with calcium hydroxide (calce viva), remained to create a hill now named Monte Testaccio, high and more than 1 kilometre in circumference.