A bit of a walk from the new terminus, but this is the 'ninfeo' that stands at what may have
been the original entrance to the Villa of the Quintilus brothers, on Via Appia Antica.
More here.. http://www.060608.it/en/cultura-e-svago/beni-culturali/beni-archeologici/villa-dei-quintili.html
Usually the only way to get into the Villa is through the grand gates, a mile or two away,
at Via Appia Nuova 1092, however it's apparently possible - from April to October and only at
weekends and on holidays - to get into the site from here (where the official address is
Via Appia Antica 290)
But I'd suggest phoning first.....