The old structure opened in the late 1800's and is in a park in the urban center which also contains the University of Pittsburgh and Carnegie Mellon University. What an interesting collection of flowers. I didn't catch how many different plant spices are represented but it must be ten thousand. The collection is broken up into logical groups such as spices, eatables, Japanese garden, roof garden, butterflies, orchids, and on and on. The web site says you can visit the gardens in 90 minutes but take a little more time so you can read the signs.