Phuong Hoang Cave: Phuong Hoang Cave is one of the largest and most accessible caverns in northeastern Vietnam. There are four main chambers, two of which are illuminated by the sun when the angle is correct. Most of the stalactites and stalagmites are still in place, although quite a few have been broken off by thoughtless sou-venir hunters. Like many caves in Vietnam. this one served as a hospital and ammunition depot during the American War. If you want to see anything, bring a good torch. The cave is a 40km motorbike ride over a bumpy road from Thai Nguyen.
Nui Coc Reservoir: A scenic spot popular with locals, Nui Coc Reservoir is 25km west of Thai Nguyen. It's a pretty stretch of water, and is a major drawcard for Hanoi residents looking to get away from it all. On summer weekends it can get particularly crowded. A one-hour, circular motorboat tour of the lake is the thing to do. You can use the water park's swimming pool, and also rent rowboats. It could be worth a visit if you're travelling to Ba Be National Park, with your own wheels, and fancy a dip.