The City of Ammaia is the most important Roman ruin  in the Northern Alentejo region. Set in the Natural Park of Serra de São Mamede, in São Salvador de Aramenha, near the town of Marvão, the ruins cover almost 25 metric acres.

The Roman City of Ammaia was only rediscovered in the last century. It has since been excavated and investigated by scientists from around the world. It is now a museum site.

For years the Roman remains were thought to be a villa, but only at the beginning of the last century did one begin to realize that what was buried in the Valley of Aramanha was an actual lost Roman city.

Built from scratch in the first century AD, it was a city with a forum, baths and temples over the next three hundred years. The city suffered after the collapse of Rome on the Peninsula in the 3rd century. By the time of the Moorish invasion  the 9th century, the remaining residents fled to high hills of Marvão - easy to defend in a time of chaos. Ammaia's stones served to build other places, walls  and monuments. The bridge would stand until the 1980s.

Pillaged, looted for stone, and buried until at the beginning of the twentieth century  the existence of a large city in that area was forgotten. In the 1950s the first excavations were carried out and in recent decades the scope was also intensified, which also was helped by new technologies.

Archaeologists now can reproduce the design and architecture of Ammaia, thanks to a technology that allowed the whole area to be x-rayed.

Although its ruins were classified as National Monument in 1949, they were abandoned until the end of 1994. From this date and with the appearance of the Ammaia Foundation, every effort has been made to study and preserve what remains of this important city. Ammaia was elevated to Civitas around the year 44/45 AD. having obtained the status of Mvnicipivm still during the century. I AD., however we only have data about the same in the reign of Lúcio Vero, in the year 166 AD.

http://www.ammaia.pt

http://ensina.rtp.pt/artigo/ammaia-radiografia-de-uma-cidade-romana-documentario/