Think Harappa Civilisation relics, artefacts from the Silk Route, war memorabilia, and a fantastic collection of miniature paintings. The museum also has over 2,00,000 works of art, both Indian and foreign, from the last 5,000 years.
They have an audio guide, too, which you can rent (carry photo ID). The National Museum is next door to the Archeological Survey of India, in case you want to drop in for a bit.
Timings: 10am – 6am, closed on Monday.