Gulangyu, separated from the main island by the 500-meter-wide Egret River, with an area of 177 square kilometers, enjoys a laudatory title "Garden on the Sea." The original name of the islet was Yuan Zhou Zi. In the Ming Dynasty it was renamed Gulang, meaning ''drum waves", because the holes in the southwestern reefs hit by the waves will make sounds like the drum.

The Dragon Head Hill, Hoisting Flag Hill and Hen Hill stand in a line in the islet. Overlapping peaks foil the blue water, white clouds, green trees and bright flowers. The air in the islet is fresh. The entire place is free from any sorts of vehicles and is particularly quiet. The residents here love music very much, and the number of the pianos possessed leads the nation, though there is only a population of 20,000 people. Thus the islet is praised as the "Piano Islet."