Castro Pretorio is a station on Line B of the Rome Metro.[1] It was opened on 8 December 1990 and is located on Viale Castro Pretorio, at its junction with Via San Martino della Battaglia, in the Castro Pretorio rione. Its exit overlooks the Castra Praetoria (the camp of the Praetorian Guard), now the site of the Biblioteca Nazionale Centrale.