Possibly my first good magical realism book. I loved this so much that I took the real name of one of the characters as my alter ego name in adventure stories I was writing at the time.
The Thief Lord plays in Venice, among kids living on the streets because they have no home, or have run away, or have a mysterious backstory. They steal and sell small things, and take care of their own. The protagonists are a pair of brothers, the older being heart-breakingly responsible for the younger. The entire worldbuilding is incredibly detailed and sucked me in back then.
There was one girl who routinely grabbed cheap books out of the trash and had built a small fort of them surrounding her bed in the old cinema they were living in. I didn’t really care for the plot or the magic – there’s a bit of moralising about growing up that was just meh – but the worldbuilding was top notch.
The Unfortunate Events series does something similar in places, but is more cruel. Kalle Blomquist has a similar feeling of children taking care of things in a serious way.