This is definitely a must-see attraction for any Steampunk visiting London. The first exhibit you come to is called Energy Hall and features full-size steam engines and has interactive features that show you the physics of how they work and give the history of how they fit into the evolution of steam technology as a whole.
But, the absolute best exhibit hall is Making the Modern world. It offers a veritable cornucopia of amazing inventions, including Charles Babbage’s Difference Engine No. 1 and a working model of a Victorian-era workshop run on a belt system.
Like the Museum of London, I would definitely recommend this as a great place to take people with mixed interests because the museum also has exhibits on the history of agriculture, real objects used in the early days of space travel and a “4D” cinema that has films on a wide range of topics.