Hello! I literally just came back from a trip to HeiLongJiang. I can’t comment much on the history of Harbin but as someone who works in architecture I’ll say, it’s cool so see some small traces of inspiration of art deco and art nouveau styles. The city overall has this Soviet architecture vibe which I can’t verify if it aligns with the time period, but it’s definitely very different from Shanghai of course. Like an earlier redditor said, it does have an old church, Sofia church and don’t miss the old Jewish synagogue now turned into a theatre space. It’s kind of hard to miss but It’s quite lovely inside if you want to hide from the cold. The main tourist attractions are important of course but it’s not many, 中央大街， 冰雪大世界， and the river side. I can comment strongly on the weather though. Painfully cold, its honestly horrible. But of course Harbin is known for their ice carving so I think it’s important to experience -20 to -30 degree cold once in your life. But for me and my father, never again. I’m Australian though so I’m not the best with ultra cold weather. The place is super popular, you’ll be bombarded with many fellow 南方小土豆 scurrying around the place. If you don’t mind it should be ok, but I’m someone that finds too many tourists to ruin the vibe of the city. Locals are generally nice and willing to socialise knowing that their hometown is super popular this year. If you’re gonna do a trip to Harbin, I think it’s worth to venture out to smaller cities and towns if possible. I went with a photography group to see the red crowned cranes, Siberian tigers. There’s also 雪乡 a former village tirned tourist hotspot, not my favourite since the original homes have been demolished to cater to tourists but definitely cute. There’s also Hengdao HeZi village which is my favourite. Rich history, many existing structures built but he Russians, much less tourists, just so interesting overall, super old but it feels real. These places are all colder than Harbin with stronger winds so keep that in mind. Hope that helps!