Hanoi is intense. It's loud and run down and the stools in most local cafes are hilariously tiny.
Hoan Kiem Lake
We spent a lot of time around this central and public space. On the weekends, the streets around it are closed to traffic so local families come to hang out. You can rent a R/C car so your toddler can rampage around the empty streets or blow massive bubbles at the crowds.
As soon as I finished my run, I was stopped by some teenagers who asked if they could practice their English. I found it charming, but we chatted haltingly and they asked their pre-set questions. The lessons continued as we rounded the lake, with students of all ages, from all over the city approaching us with their notebooks. It's a smart way to get free practice but it did loose it's novelty after the 7th encounter!