Cesta Do Praveku (1955)

aka: Journey To The Beginning Of Time

Four young boys visit a dinosaur exhibit at the New York City Museum of Natural History. They then row out onto Central Park Lake where they find a secret cave and paddle into a wondrous prehistoric world filled with the very dinosaurs they had just seen. Czech language version of Journey To The Beginning Of Time, also available here at Rare Movie Collector. With English subtitles.