Nestled beneath the Marble Tree Alleys,  this is the most concentrated mansions in Nanjing during the era of the Republic of China. Of the 287 garden houses built in that period, 225 still remain and are well preserved. They are scattered around the Yihe Road as the central axis. Each building has its own unique flavor. The buildings are of different architectural styles, American, European and Japanese Together they constitute an outdoor architectural museum of the Republic of China.