The miniatures started as souvenirs from well-known attractions on the European Grand Tour and then spread to the US. There are souvenir miniatures representing buildings from stadiums and arenas to cathedrals and office buildings. Rick's collection is of cast metal but the buildings are also made of other materials. Sometimes the model buildings were given as gifts to stockholders and other times with a purpose such as fitted to be used as a coin bank.
This is a very appropriately cool collection for an architect and the sheer number of miniatures on display is amazing.