The seats are entirely destroyed, and it is only by the oval shape and by the position of the substruction that the ruins can be recognized as those of an amphitheatre.
Of these the lowest stands on a substructionof two steps, and originally consisted of a row of eighty arches, between which stood half columns of the Doric order.
Giorgio in Velabro, is built of this stone, and the inner part of the substruction of the so-called tabularium on the Capitol.
The ruins which lie under Castel Gandolfo, on the left side of the road towards the Porta Romana of Albano, may have formed part of the substruction of which Cicero speaks.
The substructionof this temple, which has been laid bare, consists of tufa cased with travertine.
Strabo describes it as standing upon a lofty substruction of white stone, and shaded up to the top with trees.
They stand upon a substruction only excavated a few years ago, and present one of the finest specimens extant of a temple, all the essential parts of which have been preserved.
It was surrounded on three sides with columns, and in the centre was a fountain: it was subsequently occupied by the substruction arches of the baths.
All the rectangular stones of the substruction are of white marble.
The fire rests upon the broad hearth; the hearth rests upon a great substruction of stone, and the substruction rests upon the cellar.
