Different maps of the same town sometimes differ much in their detail.

The Italian Government maps of the largest scale (1:25,000) are small for our present purpose and have been issued mainly for northern Italy.
The evidence of the streets needs, however, to be checked in every case.

It would be rash to assume a Roman origin for an Italian town simply because its streets are old and their plan rectangular.

There are many rectangular towns of mediaeval or modern origin.

Such is Terra Nova, near the ancient Gela in Sicily, built by Frederick Stupor Mundi early in the thirteenth century.