It’s never nice to visit a prison, but what it does do is give you a real insight into the grizzly history of the city you’re visiting. In the case of Hanoi, the Hoa Lo prison is now a museum which shows a few sections to visitors and the rest is kept kind of under wraps. You can see how prisoners were crammed into the small cells and made to go to the toilet in cave-like places. Not a nice thing to see but if you like learning about the real history, then you’ll feel like you came away with a true sense o how it was during the war