The Experimentarium in Copenhagen is a super cool science museum where you can play with interactive exhibits, test your skills in challenges, and explore different areas like light, water, and transportation. It's huge and full of people having fun, with a staircase that looks like something out of a sci-fi movie. Plus, there's a rooftop with awesome views of the sea. And don't forget the light-yourselfie booth – perfect for some quirky photos!