PORTA MERIDIONALIS is their Roman name. As the gate which, under some assumptions of the original state of the south facade of the Diocletian palace - the sea mourned, differs completely to the other three. Modest in size, but also different in its function as it leads through the Substructures directly to the sea.

Besides its Renaissance name Aanea - Brass, it also earned the attribute Secure, as it ensured the possibility of a flee by the sea in case of attack on the Palace from the mainland. With a partial restoration, authentic door blocks indicate to the surprised visitors soon to be a two millennium old water resistance. Today they became the "main" gate as the tourists pass through them most frequently to start their guided tours with local guides, and arrive through the Substructures to the central part of the Palace.