The site of the temple of Romulus is now occupied by the church of San Teodoro, a small rotunda. The walls are of great antiquity, and marvellously perfect. In regard to the temple of Romulus and Remus, few buildings have occasioned more disputes. It is now the church of S.S. Cosimo e Damiano; the vestibule, several porphyry columns, and a bronze door of which are exceedingly ancient.
The temple of Vesta, erected by Numa, now forms part of the church of S. Maria del Sola. It is of Greek architecture, and surrounded by a portico of nineteen Corinthian columns, on a flight of steps, the whole of Parian marble. The roof was originally covered with bronze, brought from Syracuse; but that has, long since, been replaced by materials much less costly.
The temple of Minerva Medici stands in a garden on the Esquiline-hill; it is round without, but forms a decagon within, and appears to have had ten windows, and nine niches for statues. Here were found statues of Æsculapius, Venus, Hercules, the Faun, and that of Minerva with the serpent.
The church Sa. Maria in Cosmedin is supposed to have been the temple of Puditia Patricia, or Chastity, which no plebeian was allowed to enter. Pope Adrian I. rebuilt this edifice in 728, retaining the cella, and many portions of the ancient temple.
A mean-looking church, called Sa. Maria d' Ara Coeli, wholly devoid of external ornament, is supposed to stand on the site of the temple of Jupiter Feretrius. A flight of one hundred and twenty-four steps of marble, brought from the temple of Jupiter Quirinus, forms the ascent to it from the Campus Martius; the interior has twenty-two ancient columns of granite, and the whole appears to be an assemblage of fragments of other buildings. It was whilst musing in this church, "whilst the friars were singing vespers in the temple of Jupiter," that Gibbon says he first conceived the idea of writing his immortal history.
The beautiful temple of Jupiter Tonans was erected by Augustus, in gratitude for his escape from lightning. Only three of the thirty columns of the portico now remain, together with a portion of the frieze. They are of Luna marble, four feet four inches in diameter, with Corinthian capitals, and appear originally to have been tinged with Tyrian purple.