<p>The Temple of Castor on the S side of the *Forum, between the *Basilica Iulia and the *Lacus Iuturnae, dedicated in 484 B.C. by the son of the dictator Postumius who, according to Roman tradition, had vowed the temple at the battle of Lake Regillus in 493 B.C. (Livy 2.20.12, 2.42.5: <i>Castoris aedis</i>; Dion. Hal., <i>Ant. Rom</i>. 6.13.4). The temple was rebuilt by L. Caecilius Metellus Delmaticus in 117 B.C. (Cic., <i>Scaur</i>. 46 and Asc. <i>ad loc</i>.; Cic., <i>Verr</i>. 1.154; Plut., <i>Pomp</i>. 2.4), and Cicero notes that Verres made certain repairs to it (<i>Verr</i>. 1.129-54, 3.41, 5.186). The Metellan temple may have burned in the fire of either 14 or 9 B.C. (Nielsen 244), but the sources do not record this; in any case the temple was completely rebuilt by Tiberius and dedicated in the names of Tiberius and his dead brother Drusus in A.D. 6 (Ov., <i>Fast</i>. 1.707-8; Dio Cass. 55.27.4; A.D. 12: Suet., <i>Tib</i>. 20). Some fragments from the dedicatory inscription of Tiberius and Drusus have survived, but the restoration of the text is uncertain (Alföldy). Gaius converted the temple into a vestibule for his palace (Suet., <i>Calig.</i> 22.2; Dio Cass. 59.28.5), an arrangement which Claudius eradicated, and Domitian is credited with a restoration (<i>Chron</i>. 146), but there are no further traces of major renovations and scholars agree that the existing remains are mainly Augustan (cf. <i>LTUR</i> I, fig. 138; Ulrich 193, fig. 30).</p> <p>The temple, which was octastyle and peripteral in its Augustan phase, was approached by one frontal and two lateral staircases; in the Augustan period the platform to which the lateral staircases provided access served as a speaker’s platform (cf. Festus 362). At a later date this arrangement was modified and the staircase became a single frontal flight, as shown on the Severan Marble Plan (Carettoni <i>et al.</i>, <i>Pianta</i> pl. 21; Rodríguez Almeida, <i>Forma</i> pl. 13, frags. 18 b,c).</p>