Must stop museum
The architecture alone, old and new (Singapore's former historical Supreme Court and City Hall surrounded by newly integrated modernity), is an absolute reason for a visit. Traveling with kids however, this is somewhere not to be missed as there are wonderful, quality children's exhibits for both the young and old to enjoy (current 2019 one, Children's Biennale, running until end of year, childrensbiennale.com).
Don't forget to find one of the fun bright yellow vending machines selling art kits for $5 SGD. We found it to be super interactive, vast yet easily do-able, well organized - one of our favorites, making/coloring our own paper robot inspired by the book "Story of Karung Guni Boy" by Lorraine Tang and Erik Wong. Another favorite, a table called the "Social Table" where we curated and made our own digital posters from artwork in the National Gallery.
The museum is also home to some of the best restaurants in the city including two Michelin starred Odette. What was once the registration room of the Supreme Court, it is now French fine dining. Of course, there's National Kitchen by Violet Oon, Aura and Smoke & Mirrors, a fun bar at the top with amazing views of the city.