Cloaca Maxima

Useful Information

Location: Forum Romanum (Roman Forum): subway Line B exit at Colloseum and walk west down Via Imperiali.
Cloaca Maxima Mouth: on the banks of the Tiber river at Ponte Palatino.
Mouth of Truth: at the Church of Santa Maria in Cosmedin.
Open: no restrictions [2007]
Fee: free [2007]
Classification: SubterraneaSewage System
Light: LightIncandescent Electric Light System
Guided tours:
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.


~600 BC start of construction.


Cloaca Maxima (Greatest Sewer) is the mother of all sewers. The Romans once again did it first. They not only created the most impressive channels and aqaeducts, they also crated the first sewers. And the result is really impressive, works for 2,000 years with almost no maintenance. Unfortunately there is no way to visit it, seems the enterprising did not discover its touristic value by now.

The Cloaca Maxima was built because of the swamps around Rome. The location of the city was not very good, because the swamps or marshes were pest infected and the city suffered from the deseases which originated from there. So the drainage system was one of the first an most important things to built in order to make Rome a working city. It drained the water from all around into the Tiber river.

The work began around 600 BC under Lucius Tarquinius Priscus, king of Rome. Etruscan engineers supervised the work and large amounts of forced labour from the poorer classes of Roman citizens did the work. The result was a system of open drainage channels and some tunnels. The water from three of the neighbouring hills was collected and drained through the main Forum Romanum and then into the Tiber. As buildimg space within the city became more valuable the drain was gradually built over until it was completely underground.

At this time the cloaka was not used for all waste water, most private houses had cesspits. The colaka drained the marshes and the official or public buildings especially the baths and public toilets. This changed during the centuries when it became more important. The sewer system was maintained during the whole existance of Rome and afterwards. It was still in use during the Middle Ages, although sometimes in bad shape. It was finally replaced by the modern sewage system, but partly reactivated when sand from the river was

It is not possible to visit the Cloaca Maxima as a tourist. But it is possible to visit the remains on the Forum Romanum, just by walking down Via Imperiali. See the map on the Wikipedia page for more details. The mouth of the sewer, where the water once flew into the Tiber river, is located between the bridges Ponte Rotto and Ponte Palatino. So both locations are easily accessible and free- The modern access is a stairway going down to it at the Basilica Julia on the Forum Romanum, but it is closed.

La Bocca della Verità (the Mouth of Truth) is among the most famous sights of Rome. A huge circular mable relief with a face, and a hole where the mouth is. In general it is said to be the remaining part of an ancient fountain. But the oozeman (see link European Sewer Safari below) tells us its an ancient sewer grate.