[Sidenote: Porta Mugionia.] [Sidenote: Jupiter Stator.] In front of the last described buildings, which we have called the basilica, the atrium, and the lararium, is an open space, on the right hand of which, looking towards the Arch of Titus, a fragment of the earliest walls of the Palatine remains, constructed of tufa blocks taken from the hill underneath. Beyond this, towards the Arch of Titus, are the paving stones of an ancient road which was probably the approach to the palace, and to the left of this road stand the relics of one of the most ancient gates, the Porta Mugionia. This is described by Vacca as having been discovered at the end of the sixteenth century, when it was still decorated with marble. The substructions alone now remain, and close to them may still be traced the foundations of an ancient temple which can be no other than the temple of Jupiter Stator. Solinus says that the house of Tarquinius Priscus was near the Porta Mugionia, and Livy states that he lived near the Porta Mugionia. The statue of Clœlia is also said by Livy to have stood at the top of the Sacra Via which was near the Arch of Titus, and this statue is further placed by Pliny near the Porta Mugionia.[19] The remains of the temple show that it was arranged according to the cardinal points of the heavens, looking north and south. On the foundation stones are the names of Philocrates and Diocles, masons employed in building. Three old inscriptions referring to the worship of Jove were found here, and are to be seen in the Palatine Museum. [Sidenote: Cryptoporticus.] Near the ruins of this Temple of Jupiter Stator we find vast blocks of substruction which belong to the complicated ranges of buildings occupying the north-eastern end of the hill, and generally believed to have been erected by Caligula. They extend along the side of the hill over the Forum, and along the Clivus Victoriæ by which we entered, to the point which overlooks the Velabrum. The modifications and enlargements of this structure during the ages succeeding Caligula have rendered it a confused mass of ruins, and the walls and chambers now left have served chiefly as substructions for the lofty mansions erected upon them in the course of ages. From the corner of these ruins, next to the Temple of Jupiter Stator, runs a long arched cryptoporticus or covered passage, which can be entered from the ruins of this temple or from below nearer to the modern entrance gateway. It is supposed that this may have been the cryptoporticus in which, as we learn from Josephus, Caligula was assassinated on his return from the ludi palatini given in front of the palace. He is said to have turned off from the direct line of entrance, and to have passed into this covered way in order to hear and see some youths from Asia performing. The assassins, after accomplishing their end, were afraid to venture through the front of the palace, and took refuge by hiding in the house of Germanicus.[20]