The Victorian had a love of the exotic and often applied those exotic elements from their travels to their homes.
The rarest of the rare are onion domes. While widely seen in Easter Europe and Russia and parts of the "Ottoman Empire". The Onion Dome essentially has the look of an onion bulb. There were many variants of this design but they all had one thing in common. They were hard to build. Often requiring the services of a boatbuilder who understood the complex curved framing to build one. They were often prone to leak as well after a period of time. many were simply 'lopped off' and today they are an even rarer site.