Apart from central body of the Villa stands the Beacon Tower. It initially worked to communicate with military stationing over Mount St.Costanzo at Campanella headland, which was in communication with Cape Miseno, headquarter of Roman fleet, crucial spot of Roman army organization and center of loyal party. With this efficient (for that age) communication process Tiberio was able to rule the empire without moving from Capri for about ten years and succeeded to organize his defence and subsequent revenge against opponents conspiring against him during his absence. When Tiberius died, the tower's funcion turned to more limited job of beacon for shipping and doing its work throughout all Middle Ages thanks to some hermits who settled there to take care of the little church.

Downside the Villa, on the west side, where begins the declining slope towards the island center, an hefty and isolated building rises among the greenery with large walls and unusual rooms placing. It is the "specularium", a sort of astronomical observatory designed to facilitate studies by Tansillo, the imperial astrologer and also Tiberius close friend and confidant. According to a popular tradition, the Specularium was built to be base to a grand bronze statue of Tiberius riding, but there are no traces, neither material nor textual nor literary about this statue, so we cannot say it was really done and placed there.