Lost bright purple keyring with house and car keys near Rittenhouse Square in Philadelphia.

I lost my keys on Tuesday evening while walking my dog near Rittenhouse Square in Philadelphia. The keyring is a bright purple color and has a couple of keys attached to it, including a house key and a small car key. I've retraced my steps and checked with nearby shops but haven't had any luck finding them. I'm really hoping someone might have come across them.