According to Suetonius, in AD 39, Baiae was the location for a stunt by the eccentric emperor Caligula to answer the astrologer Thrasyllus's prediction that he had "no more chance of becoming emperor than of riding a horse across the Gulf of Baiae". Caligula ordered a 3-mile-long pontoon bridge to be built from impounded ships of the area, fastened together and weighted with sand, stretching from Baiae to the neighbouring port of Puteoli. Clad in a gold cloak, he then crossed it upon a horse. Cassius Dio's "Roman History" also includes the event, with the detail that the emperor ordered resting places and lodging rooms with potable water erected at intervals along the bridge. As late as the 18th century, scattered fragments were still being shown to tourists as the "Bridge of Caligula". Malloch has argued that Suetonius's account was likely coloured by his bias against Caligula; instead, he claims that "the act of bridging the Bay of Naples was an excellent—and safe—means by which to lay the foundation for [Caligula’s] military glory."