National Museum is a real time commitment — fit it in only if it's a priority.
Allow 1.5–3 hours.
The building itself — grand staircase, domed pantheon, restored interiors — is arguably more impressive than much of the collection, and the rooftop/dome views are a hidden treat. The catch: the natural-history and history exhibits are solid but conventional, and the full ticket plus the connected New Building can be a lot of museum for a sightseeing-light trip. Strong for the architecture and a rainy afternoon.