public art in particular is suuuper interesting, also art censorship, history of religious art, history of art movements or specific art styles (anything from impressionism to gran fury). or you could dive into specific artists (or even specific art pieces!). i think whatโs really cool about it is that art history can be about people, politics, religion, culture as well as the medium itself and the evolution of techniques and styles
art restoration might be an interesting topic to learn about too (but personally i just like watching these videos lol)