The Luxembourg Stock Exchange has been in existence since 1927, and there are a lot of securiities from a large number of regions traded. It is now part of the Euronext group of exchanges. It is located on the avenue de la Porte-Neuve, with the entrance surrounded by a shopping mall.
There are a lot of beautiful old, historic buildings (houses, churches) around Luxembourg. Just one example on my picture.
Simply, if you like old, historic cities it's a kind of place for you.
At the banks of the river Petrusse are lovely old houses.
Don't forget the rest of this tiny country as it holds a very special atmosphere. Maybe one can call this the true Europe as it is influenced by so many other countries that surround it.