4 Days in London

The Changing of the Guard draws big crowds and doesn't happen every day — check the official schedule and arrive early.

Same-day and discounted theatre tickets are sometimes available at the official TKTS booth in Leicester Square.

Arrive at opening time and head straight for the Crown Jewels, then join a Yeoman Warder (“Beefeater”) tour and look out for the ravens.

Sky Garden is free but needs a slot booked in advance. Or continue along the South Bank to the London Eye at dusk.

British Museum highlights: the Rosetta Stone, the Parthenon sculptures, the Egyptian mummies and the Sutton Hoo treasure. Some museums ask you to book a free timed entry slot at busy times.

Portobello Road Market is at its biggest on Saturdays; on other days the shops and cafés are still worth a visit.

Option A — Greenwich (UNESCO World Heritage Site): take the Uber Boat by Thames Clippers downriver, a sightseeing trip in itself.

Option B — Camden Market's food stalls and vintage shops, the Regent's Canal towpath towards Little Venice, then Shoreditch and Brick Lane in the evening. Day trip alternative: Windsor Castle, easy by train — check its opening days first.