Electronic smartcards called Oyster Cards offer the cheapest fares for London travel, but if you’re in town for only a few days, a Travelcard may be more convenient. These give unlimited travel on the Tube, DLR, buses and Overground rail, plus a third off scheduled riverboat fares. Travelcards can be bought for one, three or seven days, plus longer periods, with the cost depending on the zones you travel through. An off-peak, one-day Travelcard for Zones 1-2 costs around £6.60.
First Capital Connect and Southern offer services taking between 35-40 minutes, with fares priced from £8.90. Taxis can be expensive, with journeys taking about an hour and costing more than £50.
Dot 2 Dot offers a bus shuttle into central London (20 minutes; £25), 24 hours a day, seven days a week.
Road distances to London are measured from Trafalgar Square, where you can find a brass plaque marking the "centre of London" near the statue of Charles I.