Can you fit all six of these into a weekend?

Only if the weekend includes a Sunday, and it will be tight. Realistically: Sunday morning at Columbia Road, then east London for the rest of that day; Saturday for Greenwich by boat, or for Hampstead Heath if the weather is good. Borough Market is the one that suffers most from a weekend-only trip, since Saturday is its worst day. Four days lets all six sit in their best slots.

Which of these six should I do in the evening?

The British Museum and Tate Modern, both of which are free and both of which run extended hours on certain nights. Holding them for the evening keeps daylight free for Hampstead Heath and Greenwich, which are useless in the dark. Check the current late-opening nights for both before you plan around them, as the schedules have changed.

What is the best day to visit Borough Market?

Mid-week into Friday, when the full market is trading and the crowd is manageable. Saturday is the busiest day of the week by a wide margin and the start of the week is a reduced affair with fewer traders. It pairs naturally with Tate Modern, which is about ten minutes along the river.

Is the Royal Observatory worth paying for?

The ticketed part covers the Meridian courtyard and Flamsteed House with Harrison's marine chronometers, which is genuinely good if the history of navigation interests you. If it does not, Greenwich still works entirely on the free elements: the park, the view from the hill, the Shepherd Gate Clock at the gate, the one o'clock Time Ball drop, and the National Maritime Museum.

Do any of these need booking in advance?

None of the six require a paid booking to get the core experience. The British Museum and Tate Modern's permanent collections are free, though both have ticketed temporary exhibitions worth booking if one appeals. Columbia Road, Borough Market and Hampstead Heath are simply open. Only the Royal Observatory's Meridian courtyard charges, and that can be bought on arrival outside peak summer.

London, United Kingdom

London, scheduled properly

Three of these six are open on days the others are not, two are transformed after dark, and one only exists on a Sunday morning. Get the order wrong and you will see all of them badly.

Six places where the day of the week and the hour of the day matter more than the ticket

Most London itineraries are organised by geography, which is a reasonable instinct in a city this large and a poor one for this particular set of six. What links the British Museum, Tate Modern, Borough Market, Columbia Road, Hampstead Heath and Greenwich is not that they sit near each other, because four of them emphatically do not. It is that every one of them changes character depending on when you turn up, and two of them are not available at all on most days of the week.

Columbia Road is the hard constraint: a flower market that exists on Sunday mornings and is an ordinary East End street the rest of the time. Borough Market has a working rhythm of its own, with a reduced start to the week and a Saturday that is closer to a crowd-control exercise than a shopping trip. The British Museum and Tate Modern are both free, both open daily, and both entirely different buildings in the last hour before closing than they are at two in the afternoon. Hampstead Heath and Greenwich are governed by daylight and a boat timetable respectively, and in a city where the sun can set before four in December, that is not a minor detail.

What follows is not a route. It is a set of fixed points to build a route around, listed in the order you should lock them into a calendar: the immovable one first, then the ones with useful evenings, then the ones that simply need a good half-day and decent weather. Every one of these is covered in more depth on the main London dispatch; this is about fitting them together without wasting the good hours.

Field notesThe list

Columbia Road Flower Market
A narrow Victorian terrace in Bethnal Green that fills, once a week, with barrows of cut flowers, bay trees and bedding plants, traders shouting prices over each other, and a crowd so dense you shuffle rather than walk. The independent shops behind the stalls open the same morning and close with it.

Why it's on this list It is the only genuinely immovable stop on this list. The market runs on Sunday mornings and nothing else about it is negotiable, so if a Sunday falls inside your trip this is the first thing that goes in the calendar and everything else arranges itself around it.

On the groundArrive by nine for the flowers and the room to breathe, or turn up in the last hour before the traders pack up, when unsold stock gets shouted down to a fraction of its morning price.
Borough Market
The food market under the railway arches at London Bridge, where the raw-ingredient traders who make it a serious market share space with the grill stalls and oyster counters that make it a lunch destination. Busy at all times, and genuinely different depending on the day you pick.

Why it's on this list It is the second scheduling constraint, for the opposite reason to Columbia Road: it is open across most of the week, but Saturday is the day everyone else has chosen, so its position in your week is decided by avoidance rather than availability.

On the groundAim for mid-week rather than Saturday, and go for a late-morning lunch rather than the one o'clock office rush. It sits a ten-minute walk from Tate Modern along the river, which is the only natural pairing in this entire group.
Tate Modern
The Bankside power station turned gallery, with the Turbine Hall's vast sloping entrance, a free permanent collection across several floors, and a tenth-floor viewing level that looks straight across the Thames at St Paul's without costing anything.

Why it's on this list This is one of the two evening options in the group. A free collection with extended opening on certain nights is exactly the thing to hold back for the hours when the paid attractions have shut and daylight has gone, rather than spending an irreplaceable bright afternoon indoors.

On the groundCheck which nights the late opening currently runs before planning around it, since the schedule has changed more than once. Go up to the viewing level at dusk: the river and the City lighting up is better than the same view at noon.
British Museum
Two and a half million years of collected human material under Norman Foster's glass-roofed Great Court. Free, enormous, and impossible to see properly in a single visit, which is why the strategy matters more here than at any other museum in the city.

Why it's on this list The other evening option, and the one with the sharpest difference between its best and worst hours. Mid-morning to mid-afternoon it carries school groups and tour parties through the headline galleries; the late opening covers a reduced set of rooms in near-silence.

On the groundEither be at the door when it opens and go straight to two galleries, or come for the late opening and accept that some wings will be shut. The middle of the day is the one window to avoid.
Hampstead Heath
Eight hundred acres of unmanicured hill, wood and meadow in north London, with bathing ponds open year-round, Kenwood House at the top edge, and the view south from Parliament Hill that takes in the skyline in a single sweep.

Why it's on this list The daylight-dependent one. It is free and never closes, which makes it look flexible, but the entire point of it is the view and the walking, and in a London winter the usable light runs out in the middle of the afternoon.

On the groundWork backwards from sunset, which is before four o'clock in December and after nine in June, and give yourself two hours on the Heath before it. Kenwood House shuts considerably earlier than the park does, so build it into the front of the visit rather than the end.
Greenwich & the Royal Observatory
A riverside town of its own, with Wren's colonnaded naval college at the water, free maritime museums behind it, and a park climbing steeply to the Observatory where the Prime Meridian runs through the courtyard and the world's clocks are still counted from.

Why it's on this list The half-day commitment, and the reason this group is organised the way it is — Greenwich is where the standardised time that governs every other entry on this list was decided. It also has the only literal clock appointment in London: the red Time Ball on the Observatory roof drops at one o'clock, as it has since 1833, and it is free to watch from the park.

On the groundTake the river boat rather than the train, allow an hour each way, and time the arrival to be on the hill before one. The park, the Shepherd Gate Clock at the Observatory gate and the maritime museums are free; the Meridian courtyard and Flamsteed House are ticketed.

Before you goCommon questions

Can you fit all six of these into a weekend?: Only if the weekend includes a Sunday, and it will be tight. Realistically: Sunday morning at Columbia Road, then east London for the rest of that day; Saturday for Greenwich by boat, or for Hampstead Heath if the weather is good. Borough Market is the one that suffers most from a weekend-only trip, since Saturday is its worst day. Four days lets all six sit in their best slots.
Which of these six should I do in the evening?: The British Museum and Tate Modern, both of which are free and both of which run extended hours on certain nights. Holding them for the evening keeps daylight free for Hampstead Heath and Greenwich, which are useless in the dark. Check the current late-opening nights for both before you plan around them, as the schedules have changed.
What is the best day to visit Borough Market?: Mid-week into Friday, when the full market is trading and the crowd is manageable. Saturday is the busiest day of the week by a wide margin and the start of the week is a reduced affair with fewer traders. It pairs naturally with Tate Modern, which is about ten minutes along the river.
Is the Royal Observatory worth paying for?: The ticketed part covers the Meridian courtyard and Flamsteed House with Harrison's marine chronometers, which is genuinely good if the history of navigation interests you. If it does not, Greenwich still works entirely on the free elements: the park, the view from the hill, the Shepherd Gate Clock at the gate, the one o'clock Time Ball drop, and the National Maritime Museum.
Do any of these need booking in advance?: None of the six require a paid booking to get the core experience. The British Museum and Tate Modern's permanent collections are free, though both have ticketed temporary exhibitions worth booking if one appeals. Columbia Road, Borough Market and Hampstead Heath are simply open. Only the Royal Observatory's Meridian courtyard charges, and that can be bought on arrival outside peak summer.