The Northern Tropic which divides Mojiang into tropical and temperate areas is vividly called "Yin-Yang Line". With the harmony of Yin and Yang and the Tropic of Cancer through the city, Mojiang County becomes the "City of Twins" under the special advantageous environment. There are more than 1200 pairs of twins in Mojiang County, with more than 600 pairs living on the Tropic of Cancer, and the mysterious twin phenomenon also exists in plants and animals. The major sculpture on Binary Star Square is a young Hani couple. The wife on the left-hand side is pregnant, and the couple bend their legs and hold tributes to pray for the God of Heaven to bless the safe birth of their twins.