London Heathrow Airport (LHR)

Four terminals in two clusters

Terminals 2 and 3 stand together in the middle of the site, joined landside by a pedestrian tunnel with moving walkways. Terminal 4 and Terminal 5 sit on opposite edges, each with its own station and security hall, and neither can be reached on foot. The split follows the alliances: T5 is British Airways country, T2 the Star Alliance home, T3 most of the other long-haul names, T4 a group of SkyTeam and Gulf carriers.

Moving between the buildings is free. The airport trains carry passengers between the Heathrow stations at no charge, and airside buses do the same job for anyone with an onward flight. What costs is assuming: a terminal change is a leg of the journey rather than a stroll, and airlines do move buildings, so the boarding pass rather than a previous trip decides where the day starts.

Into the city: three trains, three different deals

No other British airport carries this much railway. A dedicated express runs non-stop to Paddington and is sold as its own premium product with its own ticket. The Elizabeth line leaves from the same platforms, calls on the way and then runs straight through the middle of the city — Bond Street, Tottenham Court Road, Farringdon, Liverpool Street — which for most addresses beats the express door to door.

The Piccadilly line is the slow constant: a deep-level Underground train through west London, inside the city fare system, so a contactless card or an Oyster works straight at the gate. It is the cheapest ride into town and the one still running when a delayed long-haul finally lands. Terminal 4 and Terminal 5 each have their own platforms, though not every service calls at both.

Cabs, hire cars and the charged kerb

Black cabs queue at a marshalled rank outside each arrivals hall and run on the meter — there is no posted flat fare into the centre the way there is at some European hubs, so the total moves with the traffic, plus a rank supplement. Licensed private hire and ride-hailing cars are kept off the forecourt entirely and collect from the short-stay car park beside each terminal.

Being dropped at the terminal kerb costs money, whoever is driving, and a pre-booked quote usually has that charge inside it. The free alternative is the long-stay and park-and-ride car parks, where a short wait costs nothing and a free bus runs to the terminal. Hire cars work the same way round: desks in arrivals, the cars themselves off the airport and reached by courtesy shuttle.

The border, the eGates and the purple signs

Arrivals from outside the Common Travel Area all clear the UK border, and that hall rather than the taxiway decides how long a landing really takes. Eligible biometric passports use the automated eGates, which read the chip and the face and move far faster than a staffed desk, and children may use them from a set age when travelling with an adult. Everyone else waits for an officer.

Britain sits outside the Schengen area and runs permissions of its own, checked by the airline before you board rather than on arrival: visa-exempt visitors need an electronic travel authorisation, and even a connection through a British airport can require permission in its own right. Which one a given passport needs, and whether a transit counts, belongs to the entry rules for the United Kingdom.

Connections are signposted in purple from the moment the aircraft door opens, and following the yellow arrivals signs out of reflex is the costliest wrong turn here: it puts you through the border and the baggage hall, with departures to rejoin from the landside end. Purple leads to the airside buses between all four terminals. Security is done again at the departure terminal; immigration and the belts are not.

Layovers, hotels and the night before

Hotels here are graded by walkway: one stands at the end of a covered link into Terminal 5 and another into Terminal 4, with cheaper rooms on the same walkway and a strip of them along the northern road, reached by shuttle. Compact cabin rooms inside the terminals sell rest in blocks rather than nights. Leaving the airport on a layover means the border queue twice, so it repays a generous margin.

Onward travel and the practical end

Coaches leave the central bus station between Terminals 2 and 3 for Oxford, the west and several other airports, often the only single-vehicle link to a city the trains would route through London first. Long-distance rail works the other way about: the main lines north and west start from London termini, so the country opens from the city rather than the airport, on a rail network whose fares reward booking ahead. Plenty of two-week loops of the country begin at this kerb.

An eSIM switched on before landing saves hunting for a counter, and free wireless covers the terminals for anyone who left it late. Cash machines sit in every arrivals hall, though card and phone are accepted almost everywhere the pound is spent. One continental habit does not transfer: Great Britain has no visitor tax refund on goods carried home in a suitcase, so there is no refund desk to find before check-in.