Cao Bang town is in the proximity of the Chinese border which recently made it a veritable boom town with quite new flash development. The only reason to stop at Cao Bang is to recharge your batteries for a bit before reaching other sightworthy points in the neighbourhood, of which Ban Gioc Waterfall is the best. Located right on Quy Son river which divides the two countries, from where you can either see and reach China.
Ban Gioc is a bone of border contention. At over 90 km from Cao Bang and more than 2 hours driving each way, it worths a full day's outing and looks spectacular in the rainy season, i.e. May to September, but not so exciting in the rest of the year. Another attraction is Pac Bo Cave, 54 km to the Northwest of Cao Bang, also next to the Chinese border. It was the base of Ho Chi Minh and his comrades after he returned to Vietnam in 1941 after 30 years living and acting in revolutionary movements overseas to encourage all supports for the Vietnamese patriots.