I took our to the Sicence Museum when they had lots of "hands on" stuff. Our younger son was about 3 at the time and I recall, in the Hologram area, picking him up and putting his head in a highly polished concave bowl on the wall for exactly that purpose. The reflections give you teh impression that a 3d version of you is emerging from the bowl to meet you.
It's highly likely that, having two older siblings to spark him off, he might well have enjoyed what was on offer more than yours, who is the oldest, but much of it was great fun.