Not much was known about Chinese architecture in Europe during the 1700's, but people were intrigued from wild reports, imaginative imagery, and secrecy . the term Chinoiserie is defined as "the imitation or evocation of Chinese motifs and techniques in Western art, furniture, and architecture, especially in the 18th century".
The definition of folly has a fascinating arc, while in architecture and theater it is associated with "whimsical" it also has darker meanings. From the dictionary:
1. Architecture. A whimsical or extravagant structure built to serve as a conversation piece, lend interest to a view, commemorate a person or event, etc.: found especially in England in the 18th century.
2. A costly and foolish undertaking; unwise investment or expenditure.
3. Obsolete. Wickedness; Wantonness.