Pier Luigi Tucci Imagining the temple of Castor and Pollux in Circo Flaminio “And since, according to my mind, many are mistaken in the matter of drawing buildings (for instead of doing what is right for the architect, they do what is right for the painter), I shall describe the method I believe should be followed, in order that all measurements be correctly realized, and in order that all parts of the building be identified without error” (Letter to Leo X, 18) 1 The epigraph to this paper does not boast of a presumed superiority of the architect. It simply expresses the importance of surveying the ancient monuments of Rome not only through plans, but also by means of elevations and sections. Unfortunately this procedure did not concern an ancient building excavated in 1996 in the centre of Rome and hastily identified with the temple of Castor and Pollux in circo Flaminio. The temple and the marble plan from Via Anicia In the first half of the 1st century B.C. a new temple dedicated to Castor and Pollux was built in the area of the Circus Flaminius, in the southern Campus Martius. Vitruvius lists it among the temples with a transversal cella (4.8.4) 2 and a marble plan, discovered in 1983 in Via Anicia, depicts it and its neighbourhood as they appeared in the 1st century A.D. (fig. 1) 3 . The ancient plan confirms that the temple had a cella larger than deeper, with an hexastyle pronaos and a staircase of eight steps. Its podium is indicated by two lines surrounding the exterior of both pronaos and cella, which stand for the projections of the mouldings. A narrow street separates the temple from a series of warehouses with a portico which constitutes a sort of via tecta running along the Tiber bank. Beside the temple there is a block with a raised courtyard accessible through a staircase and two porticoes, one facing 1 From Pedretti 1962, 167. 2 See Gros 1976, 143-147; F. Coarelli, s.v. Castor et Pollux in Circo, in LTUR I (1993). 245-246; De Caprariis 1996-97; Coarelli 1997, 504-515. Vitruvius mentions other buildings which however did not belong to this typo- logy (except for the temple of Veiovis on the Capitoline hill) and ‘forgets’ the temple of Aesculapius at Fregellae (see Monti 1999). 3 The plan from Via Anicia is displayed in the Museo Nazionale Romano, at Diocletian’s Baths. See Conticello De’ Spagnolis 1984; De’ Spagnolis 1985; Nicolet 1988, 173; Coarelli 1991; Lugli 1992; Pedroni 1992; Tucci 1994; Gros 1996, 19-36 (esp. 32-33, but see also 39 and 41-42); Rodríguez Almeida 2002, 43-49.