Finding Waldo is the easy part here. Every spread in this book is printed twice, side by side, and the two versions are not the same. More than five hundred differences are buried across the museum, and some of them are cruel.

The setting does a lot of work. A museum lets Martin Handford pack a page with Egyptian tablets, maritime paintings, medieval battles, vintage scrolls and gallery crowds, which means the differences hide inside frames within frames. Spotting that one tablet has an extra carved figure, or that a ship in one seascape has lost a sail, is a genuinely hard piece of visual work for an adult, let alone a child.

That is the reason this one outlasts other activity books. A standard Waldo spread ends when Waldo is found. This one has an explicit counter on each room and never runs out in a single sitting.

Very large format hardcover, thirty two pages, no pieces to lose and no batteries. It travels well, it works flat on a table with two people racing, and it stays in play for years.