It is well hidden in an atrium and seems to be connected to an art gallery. The place is rather small and seems to close early. The waitress was very friendly and the owner (?) of the place engaged us in a rather amusing and definitely interesting discussion about Austria, Vienna and their royals and politicians.
The tea was definitely good, comes in colorful mugs and is also served with honey. Their selection seems to be big and the glass of water that comes with the tea is huge, compared to other cafes.
Going there is an experience. I swear.

Very nice to meet with a larger group of people. The waiters were, so far, quite friendly. The service is good, the food delicious (at least, the antipasti plate I've had the last time). Their iced tea is homemade with a strong hint of mint, which I actually liked.
All in all a good experience. Comfortable, relaxed, uncomplicated - just as I like it.
(even though a bit on the pricey side)