The House of Wonder is a mage academy and temple of Mystra located in the Sea Ward of Waterdeep.

The temple dedicated to Mystra is located on Flint Street and Pharra's Alley, which is named after the first mistress of the temple, Pharra.

In the late 15th century DR, the temple displayed ostentatious towers with mosaics and displays of magic. Throughout the structure, violets were carefully planted in memory of Ahghairon.

https://forgottenrealms.fandom.com/wiki/House_of_Wonder