Indoor attractions in Bangkok

สวัสดีครับ! I'm visiting Bangkok this weekend. I checked the weather and there's a chance of thunderstorm which would affect my itinerary since I'm visiting mostly outdoor spots.

That's why I'm making a backup itinerary in case of a downpour. Can anyone recommend indoor places to explore other than shopping malls? I only know Bangkok Arts and Culture Center so far. ขอบคุณครับ!