Every runner carries a number around. Sub-30, sub-25, or the one from 2019 that gets quieter each time it comes up. Every runner also has a local parkrun with a hill in it, which is where the number went, and a private theory that somewhere out there is a course so flat the PB would simply fall out of them like change from a pocket.
The flat courses exist, and somebody has done the maths. The awkward part is that flat and fast are not the same thing.
Flat is not the same as fast
The most useful ranking comes from statistician Tim Grose of the Power of 10, who scores every UK parkrun from 0 to 12 on median finish times, each point worth about 30 seconds over 5K. His 2025 survey covered 835 courses. Pegwell Bay in Kent came top on 0.8; Great Yarmouth North Beach came last on 11.6, more than five minutes slower for the same pair of legs.
The scores also show how little contour lines tell you. Hackney Marshes is about as flat as England gets and ranks 249th, because most of it is grass and the wind has the run of the place. Fulham Palace, usually called the flattest course in London, sits at 361st. So what follows is flat and quick, with a note on why.
The courses
Pegwell Bay, Kent
Two laps of Pegwell Bay Country Park on gravel trail, past a nature reserve full of wading birds who will not be impressed by your splits. Ranked fastest in the country in 2023 and again in 2025. One caveat. parkrun has confirmed the route is around 100 metres short after National Grid works forced the start to move. Your PB will be real. Your 5K, slightly less so.
Walsall Arboretum, West Midlands
Three clockwise laps of the Victorian part of the park, past the bandstand, the lake and the visitor centre, almost all tarmac and generally flat. Second on the list, and busy with the sort of people whose times make the rest of us feel we have been entered in the wrong event.
Battersea, London
Two anti-clockwise laps of the south loop of Battersea Park, entirely on tarmac, third fastest in the country. The total climb has been measured at roughly four metres, which is less than most staircases. The field is big, so line up where your honest pace belongs rather than where your ambition does.
Belfast Victoria, Northern Ireland
Three laps of the lake in Victoria Park, completely flat, on tarmac and trail. The fastest parkrun times ever recorded, Nick Griggs’s 13:44 and Ciara Mageean’s 15:13, were both run here, which tells you everything about the course and nothing about what happens when you turn up. Sixth on the list, 9:30 start.
Dulwich, London
Just under three anti-clockwise laps of the carriage drive in Dulwich Park. The surface is smooth enough that the organisers recommend it for wheelchairs, the loop is an oval so there is nothing to brake for, and the official description calls it as flat as you can get. Twelfth fastest. You will have company.
Hove Promenade, Sussex
Two laps of the seafront between the Peace Statue and King’s Esplanade, dead straight and dead flat on wide tarmac. Twenty-third on the list. The catch is the wind, which the Channel provides at no extra charge. One direction feels like flying. The other feels like being tackled by weather.
Poole, Dorset
A lap of the tarmac cycle path, a lap of the lake, then back round the cricket pitch. All flat tarmac or hard-packed gravel, apart from a slight camber towards the water. Thirty-first fastest and one of the most popular parkruns in the country, so the opening few hundred metres are less a run than a negotiation.
Edinburgh, Scotland
One lap of the Cramond and Silverknowes promenade, out along the Firth of Forth and back, all tarmac, with views across to Fife that you will not look at. Fifty-eighth, and one of the flattest routes in the city. The organisers warn it is exposed to the elements, which in Edinburgh is a sentence doing a lot of work.
Honourable mentions: Cardiff and Bushy Park, together at 74th and 75th, both flat, both quick, both enormous, and Bushy is where it all started in 2004.
How to actually use a flat course
A flat course removes the hill, and with it the one part of a parkrun where slowing down was legitimate. That is the trap. With nothing to blame, it comes down to pacing, and most of us pace a parkrun like a dog just let off the lead. Run the first kilometre at the speed you can hold for five. On the seafront courses, check the wind before the start and accept that one half will be slower. The flattest tarmac in Britain does not care that you arrived at 8:58.
Kit for a PB attempt
Nothing you wear will take a minute off your time. What kit can do is remove the small irritations that get louder as the pace goes up. On an out-and-back you spend half the run staring into low sun, which is why the Brow Mop cap has a brim. Socks that stay put matter more over three laps of tarmac than you would think; the Blister socks are named after the thing they prevent. A tee that is not chafing by lap two is the difference between a PB and a finish photo of you clutching your side; the Agony tee earned its name elsewhere. The rest lives in The Kit.
Common questions
What is the flattest parkrun in the UK?
Several courses have a claim. Hackney Marshes, Fulham Palace and Battersea in London are all essentially flat. For the fastest median times, the Power of 10 survey ranks Pegwell Bay in Kent first, then Walsall Arboretum and Battersea.
Which parkrun is best for a PB?
One that is flat, on tarmac, sheltered from the wind and not so busy that you spend the first kilometre walking. Battersea, Dulwich, Walsall Arboretum and Belfast Victoria tick most of those boxes.
Why is Hackney Marshes not faster if it is so flat?
Most of the route is grass, which is slower than tarmac even when dry, and the marsh is open so the wind has nowhere else to go. Its score of 2.2 works out at around 40 seconds slower than the fastest course.
Is Pegwell Bay parkrun really 5K?
Not quite. parkrun has said the current route is around 100 metres short because National Grid works forced the start to move and there is no safe alternative. It still counts towards your total, but treat a PB there as a parkrun PB rather than a 5K one.
Related reading: the beginner’s guide to parkrun tourism covers the travel, the unwritten rules of parkrun will stop you being that person on lap one of Dulwich, and in defence of the 35-minute 5K is there if none of this matters to you.
Go and find some flat ground. Run it as hard as you can. Discover that the hill was never the problem. Suffer every mile. Still no medals.