The most interesting part of the museum are the real planes, submarines, helicopters, cars, locomotives and tram cars that are located in the very center of the building. Very interesting also the scale models of ships in the lobby and rockets on the first floor, in particular the russian lunar vehicle and the Mercury capsule. Two exhibitions are very worth visiting: an exhibition of nuclear energy, materials and disposal of radioactive waste from Krsko nuclear plant (shared between Slovenia and Croatia and located in Slovenia, 35 km away from Zagreb) in the lobby and an exhibition of every source of energy available in Croatia: solar, wind-powered, biomass, hydroelectricity, fossil fuels and thermal energies are very well examined in large displays, exhibition includes scale models of wind turbines, solar cells, smart buildings, etc. The rest of the museum is old-fashioned, a large amount of electric, electronic and mechanical equipment (multipole motors, breakers, electronic microscopes, diesel motors, equipment for drilling oil wells and mining, agricultural tools, radio and audio equipment, like an Edison phonograph, turntables "the voice of his master", and a large etcetera of devices. I believe that the exhibit of these technological artifacts could be modernized and adapted to this new era... Very interesting equipment but a museum must be more than a collection of old stuff, I will give this museum a six-star rating if it showed us these old items in a funny and modern fashion... Museum also hosts a Planetarium (which I couldn't visit) and an experiment of Tesla coils (which I could't watch either...). It is a place worth visiting, with thousands of interesting devices, but definitely needs to adapt to the times that are running, all the museum should be like the two exhibits commented before. Don't miss this visit when you are in Zagreb, anyway.