How they dug it?
Oh! it was simple enough.

A family or a burial association needed a place of sepulchre.

Well, a first gallery was excavated with pickaxes in soil of this description--granular tufa, as it is called--a reddish substance, as you can see, both soft and yet resistant, easy to work and at the same time waterproof.

In a word, just the substance that was needed, and one, too, that has preserved the remains of the buried in a wonderful way." He paused and brought the flamelet of his candle near to the compartments excavated on either hand of the passage.

"Look," he continued, "these are the _loculi_.