What is the mouth of the sea sausage like?

Oval hole. According to the official WeChat account information of Haichang Cave Scenic Area, Haichang Cave is located in the southwest of Hainan Island in China, and it is an ocean cave. Haichang Cave presents an oval cave with a diameter of 50 meters, surrounded by towering and steep rock walls, and blue sea water is under the cave. The hole extends downward, forming a cave with a depth exceeding 100 meters. There are many stalactites and stalagmites in it, forming a unique geological landscape.