Temple of Jupiter Anxur site features

Monte Sant'Angelo -- also called Monte Giove, and Mons Neptunius to the Romans -- is the last spur of the Monti Ausoni, 227 m above the sea, and the only point where that chain actually reaches the Tyrrhenian. It closes the Pontine plain to the south. The sanctuary on its summit is what survives of a Sullan-period rebuilding, and it has three parts.

The entrenched camp

The upper terrace was the military zone: a circuit of walls with nine round towers, protecting the sanctuary and tying it to the city's acropolis. Inside, a portico ran round three sides of a square open to the south, with a sentry walk behind the far arm and a set of interconnected cisterns. A small temple in antis stands at the south-west corner of the square -- a cella fronted by two columns set between the projections of its own walls.

The great temple and its terrace

The lower construction carried the great temple, 18.70 by 32.58 m, set at an angle to its own terrace and facing almost exactly south. It stood on a high podium reached by a frontal stair of twelve steps, which may have held the altar at its centre. The pronaos is nearly as deep as the cella and had six Corinthian limestone columns across the front and four down each side. The cella is almost square, 14.10 by 13.60 m, with six stuccoed half-columns applied to each flank and six at the back, a white mosaic floor edged with a plain black band, and the podium for the god's statue at the far end. It was originally wider inside and was later lined with a reinforcing wall, perhaps after a fire.

Behind the temple the terrace was cut partly into the rock and closed to the north by a portico on the temple's alignment, raised three steps and originally colonnaded, perhaps in the Corinthian order. Its interior was painted, and it was where pilgrims waited.

The oracle

On the west flank of the temple: an isolated natural rock with cavities inside it connected to one another, which carried a breath of air to the outside. Rising sea currents are what made the rites work. The rock was cased in a quadrangular opus incertum base carrying a small shrine on four brick columns with travertine Ionic capitals. A pit was dug at its foot, and the 1894 excavation found a great many lead votive offerings in it. The oracle was walled off and reachable only from the end of the portico.

The twelve arches

From the terrace a stair on the east side drops to three vaulted rooms at the lower level, and from them to the face of the terrace's substructure. That face shows twelve arcades, each opening into a barrel-vaulted room, the rooms linked by tall arched passages through the dividing walls; at the back, doors and windows alternate onto a vaulted corridor about 3.50 m wide, still plastered. Behind the corridor, lower again, is a natural cave, later regularised, which probably connected to the oracle.

The small temple

West of all this, a terrace sits where the old road up from the city arrived and ran past. It holds nine vaulted rooms in a coarser and probably older opus incertum, opening in elongated arcades between projecting bays, intercommunicating by arched passages. They keep traces of First Style Pompeian decoration -- stucco and paint imitating a marble facing -- of the third quarter of the second century BC. A vaulted corridor runs behind them, now partly collapsed, with three cisterns beyond, and a room with a black-and-white mosaic floor survives higher up. At the east end of that corridor the church of the San Michele Arcangelo monastery was installed, and ninth-century frescoes remain from it: a Madonna and Child between Saints Michael and Gabriel on the end wall, where the altar stood.

The terrace of twelve arches

The signature of the Anxur sanctuary and the thing visible from the plain: twelve arcades in opus incertum, each giving onto a barrel-vaulted room, the rooms linked by tall arched passages and backed by a plastered corridor 3.50 m wide. The whole temple platform stands on it.

The oracle rock

An isolated natural rock west of the temple, with interconnected cavities that let a breath of air escape. Rising sea currents were what the rites used. It was cased in opus incertum and crowned by a shrine on four brick columns with travertine Ionic capitals, walled off and reachable only from the end of the portico. Lead votive offerings came out of the pit at its foot in 1894.

The podium of the great temple

Little more than the podium is left of an 18.70-by-32.58-metre building that faced almost exactly south, reached by twelve frontal steps and fronted by six Corinthian limestone columns, with four more down each side.

The ninth-century frescoes

At the east end of the small temple's internal corridor, where the Benedictines of San Michele Arcangelo put their church: a Madonna and Child between Saints Michael and Gabriel on the wall behind where the altar was.

First Style painting from the 140s BC

In the nine vaulted rooms of the small temple terrace -- stucco and paint imitating a marble revetment, attributed to the third quarter of the second century BC, and so older than the great temple above.

The nine round towers

On the upper terrace, the entrenched camp: a wall circuit with nine circular towers that protected the sanctuary and linked it to the city's acropolis, with a sentry walk and interconnected cisterns behind the portico's far arm.

The temple in antis

At the south-west corner of the camp's square, a small temple with its cella fronted by two columns set between the projections of the cella's own walls.

The polygonal wall

High on the terrace, towards the west, a fragment of an older substructure in polygonal masonry survives from the sanctuary's first phase -- two terracings at different levels, replaced by the Sullan platform.