The erroneously named Temple of Minerva Medica is, in fact, a ruined nymphaeum of Imperial Rome, built in the 4th century. Nymphaeum is a building devoted to the nymphs and often connected to the water supply. The decagonal structure in opus latericium is relatively well preserved, the full dome having collapsed only in 1828. It is surrounded on three sides with other chambers added at a later date. There is no mention of it in ancient literature or inscriptions.
The structure represents a transition in Roman secular architecture between the octagonal dining room of the Domus Aurea and the dome of the Pantheon, in particular, and the architecture of nearby Byzantine churches. The diameter of the hall is about 24 metres, and the height was 33 — important from the structural point of view, especially for the ribs in the dome. In the interior are nine niches, besides the entrance; and above these are ten corresponding round-arched windows. Both the interior and exterior walls were once covered with marble.
References:The Château de Foix dominates the town of Foix. An important tourist site, it is known as a centre of the Cathars. Built on an older 7th-century fortification, the castle is known from 987. In 1002, it was mentioned in the will of Roger I, Count of Carcassonne, who bequeathed the fortress to his youngest child, Bernard. In effect, the family ruling over the region were installed here which allowed them to control access to the upper Ariège valley and to keep surveillance from this strategic point over the lower land, protected behind impregnable walls.
In 1034, the castle became capital of the County of Foix and played a decisive role in medieval military history. During the two following centuries, the castle was home to Counts with shining personalities who became the soul of the Occitan resistance during the crusade against the Albigensians.