London combines historic science collections with Wonderlab, where hands-on exhibits and live demonstrations explore scientific ideas. General museum entry is free but requires advance booking; Wonderlab is separately ticketed. Decide which experience you want before choosing tickets.

It beats Munich for the combination of an accessible free base visit and an optional experiment gallery. Exploratorium wins because hands-on investigation is its core offer. A family interested chiefly in engineering history could put Munich higher. Choose one theme, then leave time to experiment.

Sources: Visit · Wonderlab.

Photo: Ank Kumar · CC BY-SA 4.0. Resized/compressed.