Just over the border in Belgium, a regal set of greenhouses grace the northern suburb of Brussels. Located on the grounds of the Royal Castle at Laeken, 6 acres (2.5 hectares) of greenhouses were created under the direction of King Leopold II by architect Alphonse Balat and took more than 30 years to build [source: The Belgian Monarchy and VisitFlanders]. Made of iron and glass, the 19th-century greenhouses include a large collection of camellias, azaleas, palm trees and a variety of rare plant species [source: The Belgian Monarchy and VisitFlanders]. The Royal Greenhouses of Laeken are opened to the public for three weeks a year during the spring [source: The Belgian Monarchy].
The next greenhouse is located far north of Belgium in Scandinavia.