Families in Belgium.

The "Beaufort" sculpture trail along the seafront is free and excellent. Try the shrimp croquettes at Mosselbeurs or take the 1907 De Lijn coast tram (the longest tram line in the world) along the entire Belgian coast.

Climb the 365 steps of the belfry (€8) for the view; combine with the BAM (Beaux-Arts Mons) or the Mons Memorial Museum on WWI/WWII. The city was 2015 European Capital of Culture and still benefits from that investment.

Population ~500 inside the walls. The old town is a 30-minute slow walk; cross the Ourthe to the topiary park (paid, €7); the adventure park (zip-lines, climbing, kayaking) is the main draw for families. Wim Vanderkeybus runs the gourmet restaurant scene above its weight class.

You can drive or walk up. The grounds are free; the Terra Nova interpretive centre is paid (€8). Excellent picnic spot on the ramparts, panoramic view back over Namur old town. The little tourist train from the city centre is a charming way up if you have kids.

Six floors of toys from 1850 to today: railway sets, dolls, dollhouses, comics. Playful, not stuffy; younger kids get hands-on play areas. Easy combine with Mechelen's old town and Sint-Romboutskathedraal.

The 2019 audio guide by comedian Wouter Deprez is one of the funniest museum guides in Europe. The castle itself is impressive but small (90 minutes); combine with a walk through the Patershol quarter and a stop at the Gentse Feesten if it's July.

The park itself is free; pick one of the three on-site museums for a half-day. Autoworld is the easy win with teenagers; the Royal Museum of the Armed Forces & Military History is enormous and weirdly under-visited. The arch terrace is open weekends.

Walk around miniature versions of the Acropolis, the Eiffel Tower, the Berlin Wall and Big Ben — about two hours of strolling for kids who like trains, boats and the "let me push the button" gene. Combine with the Atomium for a full Heysel afternoon.

A perfectly symmetric 18th-century park with fountains, statues and a small playground for younger kids. Two seasonal café-kiosks open during warm months. Excellent five-minute escape between two museum visits — no ticket required, dogs on lead welcome.