Not a business center, but if you ever get the chance to go to the The Wieliczka Salt Mine just outside of Krakow, Poland don't miss it — absolutely stunning (and easily accessible by local public transit).
Supposedly, it was one of the Tolkien's inspirations for the mines in the Lord of the Rings. And because it's a salt mine, the air is very clean. They used to send asthma sufferers into the mines as a form of therapy.
It's an experience for sure. We toured near closing time and ended up on our own tour with one of their historians. She was able to answer a lot of our engineering questions about the mine and their approach to preservation. A fun fact is that since the mine is made of salt, the rooms and passages twist and deform under pressure and humidity. The tour for the masses is light and saltysweet, but if you have the chance to visit try calling in advance to see if you can get a guide who can delve more deeply.
There is a salt mine in Kansas too, 600 feet underground. Neat tour. I seem to recall seeing a Cylon from the original Battlestar Galactica down there.
Supposedly, it was one of the Tolkien's inspirations for the mines in the Lord of the Rings. And because it's a salt mine, the air is very clean. They used to send asthma sufferers into the mines as a form of therapy.