Birla Industrial & Technological Museum Kolkata (Calcutta)

This excellent museum is a hands-on opportunity to press buttons and yank at levers to understand – among numerous other things – how electricity conducts itself through bodies, how TV signals are broadcast, where trains and buses derive their power from, and what it looks like deep inside a coal mine. It's a hit with school groups, so you may have to jostle with kids waiting for your turn at the consoles.