How to see the world’s top sights for FREE: from museums to cathedrals, tours and galleries, the secret tricks travel gurus use to visit the greatest places on earth without spending a penny

It’s no secret that sight-seeing can be expensive. This year, for example, a 90-minute guided tour of Buckingham Palace’s East Wing will set you back £90 per person. Yet exploring doesn’t always have to leave such a hole in your wallet. With a little planning,...