Mountains with a sea, a sea with a gate.

The Sanmenhai Skylight Group is a combination of mountains, water, caves, and sky. It has mysterious underground river resources and rich and obvious karst landform features. Due to the high calcium content in the water, it usually appears a unique blue color, a bit like the sea, hence the name "Sanmenhai" (Three Gate Sea). There are a total of seven skylights, arranged in the shape of the Big Dipper, which is particularly magical. Currently, three of them are open to tourists. During the National Day holiday, the water source connected to the underground river was turbid due to rain, and the water in Sanmenhai turned Assam-colored. The scenic area also posted a notice to remind tourists that they can refund their tickets if they mind. But this did not seem to affect tourists from afar, as can be seen from the dense tourists in the waiting area. The boat tour is still quite fresh and exciting. Many places are narrow lava passages. The boatman uses his hands to hold the stones to steer the direction. Boats bumping into each other is common, and you can feel "the end of the road, but there is another world." Sanmenhai is located in the remote Fengshan County. It takes more than three hours to drive from Nanning. You can experience countless highway tunnels along the way, and the mountains and ridges along the way are quite shocking. If you have time, it is recommended to take a small loop in Hechi. There are rich tourism resources in Nandan, Bama, Du'an, etc. along the loop, which is worth the trip.