Termantia, the present-day locality of Tiermes, is an archaeological site on the edge of the Duero valley in Spain.

It is located in the sparsely populated municipio of Montejo de Tiermes (Soria, Castile and León).

[1] It is remarkable for its impressive site on an arid red sandstone hill and for the way buildings have been carved in the solid rock.

The wealth of Termes in Celtiberian and Roman times came possibly from sheep farming (there are indications of an annual transfer of flocks between the northern plateau and Extremadura) and from deposits of iron ore and other metals in their area of influence.

[citation needed] The conquest of the Iberian Peninsula by Rome was a long process that lasted two centuries.

One of the highlights was the Celtiberian Wars that led to the incorporation of much of Celtiberia up to the middle of the upper Duero after the fall of Numantia in 133 BC.

From 70 BC the city began major urban renewal, using the three terraces of the hill, especially the middle, where the most important buildings would be located in the future.

Termes was assigned to the Conventus Cluniensis and thereafter the Hispanic-Roman city began to take shape, whose period of greatest splendour was between the first and second centuries AD.

It was endowed with large public buildings, two fora (first Julio-Claudian and later a Flavian forum), thermal baths, a possible theatre, an aqueduct and urban development suited to the location of the city on a sandstone bluff surrounded by river gorges and forests.

The archaeological remains are located on several terraces and in the southern plain: Flight of steps carved into the rock: monumental public space of uncertain date and function, with steps divided into sectors and access stairways, near the door of the Sun, one of the ancient entrances.

Canal aqueduct: carved into the rock, it brought water from the hill to the Roman city, partly underground West Gate: pedestrian access to the city "House of the aqueduct", residence of 1800 sqm with 35 rooms on different levels connected by stairs.

In the case of the western structures these are thought to be earlier than the Roman city of Termantia/Termes, i.e. part of the Iron Age hilltop settlement.

The eastern structures are without fixed chronology and could be part of a previously unknown extension of the Roman settlement.

The European LIFE Programme provided funding in the period 2003-2006 to develop eco-cultural tourism in what is an economically marginalised area.

Encinares de Tiermes, a Site of Community Importance, was designated a Special Area of Conservation for the species in 2015.

ARGENTE OLIVER, JL et al.: "Tiermes II (Campaigns 1979-1980) Excavations in the Roman City and the Medieval Necropolis.".

HOUSE MARTÍNEZ, C. de la and others: "Tiermes III Excavations in the Roman City and the Medieval Necropolis (Campaigns 1981-1984).".

Edition directed by JLArgente and basically completed in 1997-1998, reviewed by the archaeological team of JL Argente (Alberto Bescós, Santiago Martínez Caballero, Arturo Aldecoa Ruiz and others) in 1999-2000 and published by the JCyL in 2001.