Ah, yes: that's every Italian construction worker's worst nightmare! Every single time somebody digs a hole over there, an archaeological discovery is made: it makes building in certain areas next to impossible.

Most of the time, if the find is not particularly interesting (say, the remnants of a Roman street where you expect a Roman street to be, or the cellars of a 9th century monastery you already knew stood there), they are photographed, protected with special fabric and sand, and re-buried under whatever it is you're building.

And there are times construction companies try (and sometimes succeed) to hide archaeological finds so their project is not halted for years: when an Etruscan vase pops out while you're excavating the foundations for a 10-million euros mall, the prospect of bankrupcy is very real.