-Some info about this castro (source): "The Castro de Santa Trega is a Galician fort and archaeological site located on the hillsides of
Mount Santa Trega. At 341 meters (1118 feet) above sea level, the fort
can be found in the southwestern Galician municipality of A Guarda (Pontevedra). The site is strategically located overlooking the mouth of the river Miño. Belonging to the Castro culture,
it is the most emblematic and visited Galician fort."
"Santa
Trega is a ‘Castro-Roman’ settlement. which was inhabited between 100 BC
and 100 AD, in a period when the process of Romanisation of the
northwest of the Iberian peninsula
had already begun. Despite this, the construction system reflects
techniques that respect the Castro tradition and has seen very little
Roman influence. This style is dominated by the use of circular
structures.
Only a small percentage of the estimated size of the settlement has been
excavated so far. At present only the northern part, excavated in the
80s, and some structures at the top of the mountain are open to
visitors. It is bordered by a wall which surrounds a stretch of land
more than 700 metres (2300 feet) north-south by 300 metres (984 feet)
east-west."
"Barring
a few exceptions, almost all of the stone structures are free-standing
dwellings with circular or oval foundations. The vast majority of these houses are of small dimensions and sit
directly on the bedrock with their walls being covered with a lime and
sand mortar. Traces of pigmentation found indicate that the plaster on
the walls would have been tinted different colours.
Many of the dwellings have a foyer which is considered by experts to be a
sign of Mediterranean influence adapted to maintain the characteristics
of indigenous construction. Many monolithic door jambs and lintels have
been found decorated with intertwined geometric shapes and rope-like
moulding. In addition, embedded in the walls, cylindrical monolithic
blocks of small dimensions have been found decorated with geometric
shapes such as spirals, triskelions, Celtic roses, or pinwheel designs.
Other elements such as plinths present similar decorations in addition
to representations of animals."
"Not all of the stone structures discovered at Castro de Santa Trega
served a residential purpose. In particular, one type of building
appears to be storehouses which possess a less elaborate and less
careful construction than the neighbouring houses. Inside these
buildings, remains of amphoras, a mill, carving stones, etc. were found.
The urban distribution of the settlement is characterized by groups of
buildings forming individualized clusters. These clusters are known as
“family or household units” and are formed by dwellings and storehouses
set around a small, often paved, communal courtyard.
The site's urban planning includes a complex network of rainwater
drainage channels located under the pathways, as well as sometimes on
the surface, sculpted on the base rock and covered with slabs."
-Note and clarification: I tag this post as 'Celtic Spain' and 'Gallaic Celts', but it's to be noted that according to Classical authors, the "southwest corner of modern-day Galicia was populated by the Grovii or Grovios community" and that "Pomponius Mela
stated that all the populi [of this area] were Celtic, excepting for the Grovii. Pliny
also rejected that the Grovii were Celtic, he considered them to have a
Greek origin. They cooperated with the local Gallaeci tribes as seen in
the aftermatch of Viriatus death" (Source).
So if this is true, this castro would not have been populated by a
'Celtic' people. Still, it's a people very much related to Castro
culture and influenced by nearby Celtic peoples (the Celtic-style decorations in the houses is a sign of this). This, in addition to the fact that Castro culture is mostly associated with Gallaic Celts and other
Celtiberian peoples, is why I have decided to still tag the post about this specific castro as 'Celtic world' and the like.