The former home of Hernán Cortés, the Casa de Francia (Las Damas 42) is purportedly where he organized his brutal plans for conquering the Aztec nations of what is now modern Mexico. It served as a residence for nearly three centuries until it went through a series of government-owned incarnations and now houses the French Cultural Alliance and French Embassy.
Although visitors cannot venture into the building (except for the lobby), walking past you cannot help but admire the facade. It is made of stone and is thought to be from the same designer as the Casa del Cordón [1].
Links:
[1] http://www.moon.com/destinations/dominican-republic/santo-domingo/sights/ciudad-colonial/casa-del-cordon