Victoriahuset (Victoria House)

Hidden near the royal Brunnsviken Lake is the Bergian Garden, an 18th-century academic botanical garden. The garden's most intriguing structure is its unique 20th-century aquatic greenhouse, which was built specifically to house tropical lilies. This greenhouse is not only unusual in Sweden, but also in most of Europe, as very few original Victoria greenhouses have survived since the time of their popularity. 

The greenhouse was a brainchild of Bergianus Veit Wittrock, who had great scientific interest in aquatic plants and algae. After much lobbying, he managed to get approval from the Royal Swedish Academy of Sciences in 1899, and the greenhouse was quickly erected.

The literal and figurative centerpiece of this greenhouse is the Victoria Lily, the largest waterlily species in the world. Wittrock also planted many other species of lilies and aquatic plants inside, which then were bred and studied in this simulated Amazonian environment. This was not an easy task in the early 1900s, especially in the Swedish winter, when the greenhouse had to be kept warm with coal fires.

The structure itself is built from cast-iron and dome-shaped glass, an incredibly heavy construction that is disproportionately vulnerable to the humid climate inside the greenhouse. It was restored in the 1980s and the early 2000s. It's currently being recognized as a national monument of high protection value.