"meaning that a pyramid has at least three triangular surfaces (at least four faces including the base)."
these shapes has no base.

Thanks friiskiwi, I replaced the pic.

great shot, much better in every way.

Beautiful

That's very interesting, given the surrounding architecture - what's its story?

Thanks kyricom
The pyramid was built about 18 BC–12 BC as a tomb for Gaius Cestius, a magistrate and member of one of the four great religious corporations in Rome, the Septemviri Epulonum.
This is the link to wikipedia page:
http://en.wikipedia.org/wiki/Pyramid_of_Cestius

the pyramids in Italy, there is everything