Here are some photos of a Nymphaeum I slapped together for my Roman provincial town (in progress).
A Nymphaeum was a place people could get fresh water from--either a natural spring that had been "beautified" or a reservoir containing run-off from an aquaduct. The Nymphaeum was dedicated to the "nymphs", but from examples I've seen the patron who sponsored it could decorate it as he/she pleased, often adding statues of her family.
My Nymphaeum is much simpler than that (actually it doesn't quite meet how I wanted it). But for the moment, it gets by and adds a roughly Roman-ish look to my backwater (no pun intended) village.
If you'd like a more personal description of a nymphaeum, check out "The Murder of Regilla" (Sarah B. Pomeroy), a reconstructed biography of a Roman woman married off to a rich Greek (Herodes, a tutor of Marcus Aurelius). She commissioned a Nymphaeum at the site of the Olympic games during her stint as the priestess of a temple there. The statues included a dedication to the emperor and statues for all her children.
My Nymphaeum limits itself to the emperor... Trajan or Hadrian, by my target era.
-Tim