The Horrea (warehouses) of Hortensius (A), perhaps built in the late Republican period (1^st century BC), are one of the most ancient examples of such buildings in Ostia and maintained their original level over time.

They have a large internal courtyard, surrounded by tufa columns, onto which open the cellae (rooms for storing goods) in opus reticulatum.

Between two cellae was a small temple (B) built by Lucius Hortensius, the captain of the fleet at Misenum, who is named on the mosaic floor.

Mosaic floor of the shrine (B), with a solar disk in marble and torches at the sides
(Studio 3R)
L. Hortensius Heraclides (?), captain of the praetorian fleet at Misenum, had the small temple built in fulfilment of a vow. The priest Julius Victorinus had the mosaic laid at his own expense.

The nearby Horrea of Artemis (C), so-called after the discovery of a painting representing the goddess and built in the Trajanic period (AD 98-117), also have an internal courtyard; they were installed over an earlier building of commercial nature, telling us that the area was used predominantly for the storage of goods already in the 1^st century BC.

Axonometric reconstruction of the shrine (B) (T. Bakker)

Fragment of a fresco depicting Diana the hunter, from the Horrea of Artemis (C)