Germany's family activity infrastructure is comprehensive across all 16 federal states. The Deutsches Museum in Munich — the world's largest science and technology museum — has 28,000 exhibits including the first German submarine, a reconstructed salt mine, and a full-scale coal mine that children can walk through. The Europa-Park in Rust, near Freiburg, is Germany's most visited theme park and consistently rated one of Europe's best, with 13 European themed areas and a winter season including ice shows. The Miniatur Wunderland in Hamburg — the world's largest model railway layout, with 16,000 metres of track and miniature scenes including a functional airport — has specific child programming around its operational control room. The Berlin Wall Memorial, Neuschwanstein Castle, and the Cologne Cathedral tower climb each add heritage registers at different scales.