Tickets: No tickets are required, but the parking fee is more expensive. It costs 12 yuan to enter the parking lot and there is no invoice. The Tropic of Cancer sign tower on Nan'ao Island is the 11th Tropic of Cancer sign tower in China. Every summer solstice noon, when the sun directly shoots the Tropic of Cancer, the sun will pass through the round tube of the center of the ball above, projecting the center of the platform. The natural gate is right by the sea, and there are many cruise boats and yacht facilities on the seaside, which are more entertaining.