Cuc Phuong National Park is about 50 kilometers (30 miles) south of Hanoi. In the U.S., the way to a national park will generally be more obvious. Vietnamese national parks generally do not have two-lane freeway exits with arrows pointing. There was a small sign near the edge of a village and that was the way, on a good road.
Cuc Phuong consists of a limestone massif, through which a relatively shallow valley exists. This, despite that in limestone riddled with cave systems underneath, continuous valleys often do not exist because water on the surface soon disappears down a sinkhole into the cave system. Maybe this one constitutes a solution valley--I don't know. A relief model of the area in the visitor center is helpful in understanding the park's topography.
Xuan Hung and I walked a 7 kilometer loop that started beside the visitor center. The trail was excellent, often consisting of concrete steps up and down considerable hills. In other places, stones had been laid to make the trail. My guess is that these improvements are necessary to prevent erosion during the rainy season. Our walk went near a small cave where prehistoric men had lived, and arrived at the "Thousand Year Old Tree." It was another really good look at some really dense forest, and into at least one large sinkhole. More up and down, and we arrived back at the visitor center and a very welcome lunch.
Just outside the gate of the national park is the Primate Rescue Center. Here, several endangered species are being rescued from otherwise-impending extinction. This includes a species that is the most endangered of any primate in the world. Vietnam is to be commended for doing this.
President Ho Chi Minh declared Cuc Phuong a national park, saying that "forests are like gold." It was one of his last acts.