Miróbriga

The name of Castelo Velho (portuguese for Old Castle) is a recurrent folk toponym for ancient sites and ruins, usually referring to sites predating Roman occupation. Material culture indicates a strong continental (celtic) influence, and, if this is really is the site of Mirobriga, the suffix -briga is also an indicator of the ethnic-cultural nature of the inhabitants.

The current state of the investigation suggest that the earliest occupation may go back to 9th century BCE. However, the known structures date only to the 4th–3rd century BCE.

This settlement is thought to have occupied only the hill of Castelo Velho and its slopes, an area of about 11,800 m^2.

Because investigation has mainly focused on the Roman remains, the Iron Age occupation of the site is still largely unknown. Only one building has been excavated. It is usually referred to as the "Celtic temple", although its sacred function is still debated and could have equally been a domestic building.[4]

In Roman times the forum occupied almost the entire hill, possibly destroying the previous settlement.[2]

By about the second half of the 1st century Roman occupation began, expanding the site and occupying an area of 28,000 m². At this time the thermal baths and paved road along the southeast were constructed, reflecting the Flavian economic prosperity.[2] Around the first half of the 2nd century, the construction of the Oriental baths and hippodrome was begun, followed by the second phase of construction in the second half of the 2nd century and 3rd century.

Around the second half of the 2nd century, there were signs of abandon, that may reflect the period of political crisis caused by barbarian invasions during this period. By the end of the 4th century, there is a marked reduction in the population, although a level of continuity persisted on the site: primarily around the small Chapel of São Brás.[2]

To the east of the baths is a small, single-arch bridge (at 38.00926°N 8.6836°W / 38.00926; -8.6836 (Bridge)), that provided access along the west–east access that leads to the Forum (at 38.01042°N 8.68393°W / 38.01042; -8.68393 (Forum)), an Imperial temple (to worship the Roman Emperors) and a temple dedicated to Venus.[2][3] Between these two are the remains of an older temple dedicated to the local divinity. North of the forum are the ruins of the market and the visitor's houses, separated by another road.[2][3]

The settlement is structured around Roman roads with many paved accesses. Around the west–east axis are the ruins of the residential homes. To the east, are the former baths constructed over a canal and composed of two buildings in a "L" shape ("Western Baths" and "Eastern Baths", at 38.00932°N 8.68407°W / 38.00932; -8.68407 (Thermae)).[2][3][5] Each building has an entry into the massage hall, a gymnasium, changing room, the bathing space, which included the frigidarium (cold baths, tepidarium (warm baths) and caldarium (hot baths), and a communal latrine.[2][3] The halls are warmed by a hypocaust system that heated the floors of baths, which was located in the south part of the buildings. It was a subterranean system formed by pillars and arches, with tile, that allowed the circulation of warm air to produce heated environments, supported by kilns.

The Circus, located at 38.00224°N 8.68369°W / 38.00224; -8.68369 (Circus), was a rectangular space with curved seating on the northern end, while segmented seat on the south, used for chariot or horse races.[3] It was a 370 metre by 75 metre space, bisected by a spine with posts on either end and a triumphal arch on the south entrance.[2]