Hello how may I help you? I want to know something I can help you with any world record. Where is the tallest indoor waterfall? The worlds tallest indoor waterfall is at Gardens by the bay. And where is the tallest waterfall? Singapore Interesting. Where is that Gardens by the bay? It is in Singapore Same? no I am sorry the worlds largest waterfall is in Venezuela called Angel Falls. Okay thanks. To clarify "Gardens by the Bay are indoors and Angel Falls is outdoors. Thanks. Anytime.