Hello how may I help you? I would like to know where the tallest indoor waterfall is located please. Gardens by the Bay has the world's largest indoor waterfall Thanks for that informtion. information* You're welcome. That is located in Singapore. Great! Can you now tell me where the tallest outdoor waterfall is? Victoria Falls is the largest natural waterfall, It's in south africa. Awesome! The Victoria Falls are 355 feet high Thanks for the information. I have no further questions! Have a great day!