So after eating at Tako, I accidentally ended up wandering thru Market Square on my way to the PPG Towers - those two spaces are actually interconnected so it all worked out!
In former times, this square might truly have been an older, European style market with the butcher, baker, candle-stick maker. But now it's morphed into a restaurant square with maybe one or two hold out produce stores. The empty space in the middle is great to get night time photos of the city skyscape but it's also surrounded by outdoor dining tables from those aforementioned restaurants so really if it's busy, you are wandering past as people are eating which I feel is sorta weird (but maybe that's just me).
It's a nice square however, so definitely wander past.
Note: #332 of Yelp 100 challenge for 2016