Originally referred to as a Suggestum or Suggestus, it was also used as a Tribunal. The platform or stage was consecrated as a templum and used by the augurs to look for warning signs from the gods. It obtained the name of Rostra at the conclusion of the great Latin war, when it was adorned with the beaks (rostra) of the ships of the Antiates.
There were actually several "Rostra's" in Ancient Rome. Five separate Rostra were built at a different time periods, and only the Rostra Vetera was absent when the other four had stood together within the forum. During the Republican Era the Rostra Vetera was built along the outer ring of circular stepped seating that doubles as the steps to the Curia Hostilia (this was later filled in). Caesar erected his own rostrum when he redesigned the forum. He placed his at the foot of the steps to the Temple of Saturn where he had made several of his speeches. Augustus later had this enlarged. This rostra became known as the Rostra Augusti. The Rostra Juli is a later platform at the foot of the steps to the Temple of Caesar. The Rostra ad palmam was built during a later time period of the Empire.
Each had a similar look and use but were all designed after the original Rostra Vetera which was built in the 4th century BC.
The original rostra within the Roman Forum is the place where many of the Roman Republics great orations took place. Cicero is famous for his diatribes, many that were made from this speakers platform. It is also where Mark Antony had Cicero's hand and head displayed after his murder.
The structure is described by Niebuhr and Brunsen as such; "that it was a circular building, raised on arches, with a stand or platform on the top bordered by a parapet; the access to it being by two flights of steps, one on each side. It fronted towards the comitium, and the rostra were affixed to the front of it, just under the arches. Its form has been in all the main points preserved in the ambones, or circular pulpits, of the most ancient churches, which also had two flights of steps leading up to them, one on the east side, by which the preacher ascended, and another on the west side, for his descent. Specimens of these old churches are still to be seen at Rome in the churches of St. Clement and S. Lorenzo fuori le mura."
A number of honorary columns and monuments had been erected on the Rostra Vetera. At one point the Senate threatened to have them hauled off if the owners did not do so themselves.
Julius Caesar began his Rostra after a redesign of the Roman Forum. He buried the original Rostra and began his but it was not completed until after his death by Augustus. The Augustus Rostra had the following monuments placed on its stage; a taller one in the middle, carrying a statue of Jupiter (the patron god of Diocletian), the others, the Augusti and Caesars when Diocletian visited Rome for the first time in AD 303 to celebrate the twentieth year (vicennalia) of his reign and the tenth year (decennalia) of the Tetrarchy.
Adjacent to the Rostra is an unassuming brick-built circular construction, some two meters high and two meters in diameter. This is the Umbilicus Urbi, the nominal centre of Imperial Rome, from which all distances to distant towns and cities was reckoned. The Lapis Niger, the ancient shrine that was said to be the grave of Romulus, first king of Rome, lies next to the Rostra.
The ruins now visible of the Rostra are an early twentieth-century restoration. There is a debate by Archaeologists as to which Rostra this may be, however it is commonly believed to be that of Julius Caesar and Augustus.