Come sit on the ceiling with me in Ljubljana!
Like many cities, Ljubljana also has a museum dedicated to illusions: ours is called the House of Illusions and it is quite fun. They have various optical illusions and most are interactive, where they encourage visitors to take photos and explore the illusion.
The house features a visual vortex, which creates the feeling of spinning while standing still, several interactive rooms with changed perspectives, mirrors, light play, classical optical illusion images and also a section with mind games, where you can try your head at solving different puzzles and problems. Last time I went, we spent nearly an hour at the mind games section, as they are much harder than they appear!
The gift shop is of course appropriately stocked with aesthetic mind games, mostly made of wood. If you have some spare time, I’d definitely recommend checking it out, both for visitors and locals, as the entrance fee is quite reasonable for what you get. Everything is also translated into English, German and Italian.