A very ancient building at the city wall of Tusculum was roofed in the same way, and so was originally the well-house (-tullianum-) at the foot of the Capitol, till the top was pulled down to make room for another building.
The gates constructed on the same system are entirely similar in Arpinum and in Mycenae.

The tunnel which drains the Alban lake( 18) presents the greatest resemblance to that of lake Copais.

What are called Cyclopean ring-walls frequently occur in Italy, especially in Etruria, Umbria, Latium, and Sabina, and decidedly belong in point of design to the most ancient buildings of Italy, although the greater portion of those now extant were probably not executed till a much later age, several of them certainly not till the seventh century of the city.

They are, just like those of Greece, sometimes quite roughly formed of large unwrought blocks of rock with smaller stones inserted between them, sometimes disposed in square horizontal courses,( 19) sometimes composed of polygonal dressed blocks fitting into each other.

The selection of one or other of these systems was doubtless ordinarily determined by the material, and accordingly the polygonal masonry does not occur in Rome, where in the most ancient times tufo alone was employed for building.