Didn't feel like just taking the train back to Hanoi, so I got on a rickety local bus south to a big lake, at Thac Ba. It's so off the tourist trail that it took me an hour to find a hotel - not labeled as such of course - ignoring several locals explaining that no hotels exist but fortunately they could offer an enormously expensive scooter ride to Yen Bai an hour away. No thanks.
The reward was a village completely unspoiled by tourism. No souvenirs can be bought there. Walking a few minutes in any direction put me into valleys, fields, or to the lake, or the river leading there. As usual in small villages, I was quickly surrounded by curious people, where one half wanted me to take pictures of the other half. English not needed for having fun.