Aldenham parkrun

This parkrunday I visited Aldenham parkrun for the first time. The original plan was to return to Mole Valley parkrun to mark the anniversary of my first visit a couple of years ago and the changes in personal circumstances that marked the start of my running performance decline. But I wasn’t really keen to experience the brutal climbs during another heatwave weekend, so I changed plans last minute.

Aldenham parkrun is actually pretty far from where I live, but it was my NENDY before my visit. Parkrun tourism is getting more challenging, even for a spoiled London boy. Luckily, there is a nice cluster of events to discover in this area and I still have plenty West and South of London too. The event attracted me for his flat profile and the reservoir. The former delivered, but there is much more to this Country Park than the water. It reminded me a bit of Leybourne Lakes parkrun: a location with much more to offer than you would expect.

This is a LonDone+ venue: technically outside of London but within the M25. Part of the busy NW cluster around Watford, its location will make it an event that is equally easy to reach for Londoner and people coming from outside. If anything, if you don’t have to go back into London afterwards, you have hit the jackpot.

Anyway, enough with my rumblings. It’s time to dive into some more info about Aldenham parkrun!

Trip to Aldenham parkrun and parking

Aldenham parkrun is hosted by the Aldenham Country Park. As said above, while the location near Watford is not technically part of London, it is still within the M25. This makes for relatively commute by car, but it doesn’t seem to be very close to the peripheral TFL network.

According to the official event site, the closest stations is Elstree and Borehamwood. It is a mainline station served by Thameslink, with services to St. Albans, Luton, Kent and Sutton. Pretty good networks, since Thameslink also intersects tube lines in several locations, but unfortunately, it will not get you very close to Aldenham parkrun meeting point. According to the event site, you will still be about 3k or 40mins walk away from Aldenham Country Park. The site suggests a bus line that gets you roughly halfway. However, given the slightly trick location I would recommend using the postcode on Citymapper, to be safe.

If you are driving, you are likely to have to get on the M25 and then on a short selection of local high capacity roads. The site lists the A5, A41, A1 and M1 as the location options. I am not enough of a motörhead to distinguish them: all I know is that from Wimbledon, I headed on the M25 towards Watford and then, when I left it I had another 10 minutes or so on pretty convenient motorways.

When you reach the park, pass the barrier and you will be welcome by a very large car park. The Country Park operates a plate recognition system and no tickets need to be collected. When you leave you will have to pay at the barrier (contactless only) or get a tocken from the shop. As of June 2025, it costs flat £5.5 regardless of how long you stay there.

Aldenham parkrun: start and briefings

At one end of the very large car park, you will see the toilet block, at the other end the cafe. The meeting point is on the inner section of the car park, towards the cafe.

Parkrunners tend to congregate next to the start line, on tarmac. This will be the only part of the course that is actually on tarmac. Not a big difference on a hot and dry June day, but I am sure it is an important detail in winter (and autumn, and spring… we are in the UK after all).

Close to 9pm, the excellent loudspeaker system called tourists and first timers for the First Timers briefing. It was helpful and well delivered, explaining the slight quirk in the course: a small difference between the first and the second lap. It also stressed how lucky we were to be running on a dry day: this course must be fun when muddy.

Then a nice Main Briefing, with the RD sided by his young daughter welcoming the many tourists of the day and delivering the usual announcements. On the day, the local deputy mayor also made an appearance, delivering a brief speech. Then it was time to head in the right direction and get ready, since everyone was already more or less on the start line.

Then, I heard the RD start the countdown. ‘3, 2, 1, go!’. It was time to go.

Aldenham parkrun course review – star ratings

Aldenham parkrun course review – route highlights

There were 154 parkrunners on the day of my visit to Aldenham parkrun. This seems to be on the high end for this event, with events since April showing fairly volatile attendance levels between roughy 100 and 150. During winter months, attendance seems to fall slightly and be bound in a 70-100 range. Some seasonality is to be expected for this event: even volunteers stress how mud is a presence to reckoned during wet months here. I also think that while with this level of attendance the course rarely feels congested, there are several sections where paths get pretty narrow, so the event does not seem suited for much larger fields.

While course congestion might be a bit of an issues where the trail gets narrower, the start line is very wide and open. I do not think there are any tricky areas along the course and most turns are wide and open.

The course is fully on trails, except the first straight on tarmac through the car park. I ran in road shoes and it was totally fine, but it was June during a heatwave. The frequent reminders it gets muddy in winter are a strung suggestion you should bring your trusted trail pairs when wet. The path also gets rather narrow in places, with some areas barely wide enough for two people. Overtaking might get slightly tricky here and there.

Elevation-wise, this is definitely a flat course. At 20m over 2 laps, stats confirm my perception. There are a few very minor inclines when transitioning from one segment to the next, but they are never more than 5/10 metres long and they are barely noticeable during the run.

Course layout is pretty simple: 2 laps around the reservoir, keeping it on your right. You only really run by the water for 1 short straight, but it’s always there after the shrubs. The first lap adds a section to stick to the side of the lake avoiding the car park area, while the second lap avoids it and gets you straight onto the tarmac for the finish funnel.

A quick Relive route plot is on my YouTube Channel, with longer video highlights embedded below.

After the main briefing, everyone is already lined up by the wide start line on tarmac, at the cafe end of the car park. The start is not congested and comfortable, with plenty of space on a wide lane between two rows of parking spots. The first couple of 100 metres are in the car park, with a few non-parkrunners watching the human wave with surprised faces. At the end, a gentle right turn gets you on a trail and under tree cover. Turn right soon afterwards and after 10m you reach a small bridge that acts as the entrance to the lakeside segment. The bridge is relatively narrow, so you might have to slow down a bit here, but it’s not too bad.

When you leave the bridge, you start a long(ish) straight segment running right by the water. It is fully exposed, so this is going to be fun if windy or rainy and, rarely, if the sun is strong and hot. Neither of those applied on the day of my visit, so I quite enjoyed running by the water. The path is smooth and regular here and wide enough to overtake without too many issues. You keep going until the end of this side of the reservoir and then start going under tree cover again. Soon after that, turn right again and climb a short ramp before completing the corner with a right turn again.

After a short segment on a very narrow path with tall grass on both sides, it is time to start the next long side of the lakeside path. Now we are under tree cover, with vegetation on both sides and rare clearings opening the views up towards the water. This is again rather flat, with a few twists and turns to keep things interesting. At the end another turn and, you guess it, it heads right again. This side is shorter, under more mature and taller trees with nice clearings but no views of the water. Soon, turn hard left and cross another little bridge, to head slightly further away from the reservoir. Soon after you leave the little bridge, turn right again to continue along this side of the course.

At the end of this segment, turn 90-degrees right and leave the little forest, joining a path with trees on your right and the sheep farm on your left. The path is rather narrow again here. On the left, the sheep are quite far, but you can see them already, but worry not, there will be busier kebab areas. Keep going to the end until you reach a crossing with a volunteer. Turn right here during your first lap and left at the end of the second. As you turn right, you run by more grazing fields and these were full of sheep on the day of my visit. All these sheep were by the fence human-watching and they were extremely vocal. I don’t speak sheep, but I suspect they were asking us why on earth we were running during a heatwave.

During the first lap, this diversion soon goes back under tree cover and it runs roughly along the reservoir once again. But you don’t see much, because you will be again fully under tree cover, this time taller mature trees with large clearings underneath. Nice area to run through. Then you eventually turn left and head for the car park, alighting roughly were the start line was. Turn 90-degrees right here and do it all again, up to the crossing point with all the noisy kebabs.

Once you turn left there, there is a scenic straight under well tended trees first, then a left turn to cross the picnic area behind the cafe. Get through it and you are in the car park again, about 50m away from the finish funnel. Sprint through that last bit and you are home.

Congratulations on completing Aldenham parkrun!

Facilities at Aldenham parkrun

Aldenham Country Park is a very nice green (and blue) area with a lot to offer. There are several play areas, including a small but charming crazy golf area, and a large picnic area by the cafe. But the two center pieces of the park are the reservoir and the large farm. The latter can be visited (tickets needed), with a guided walk and plenty of animals.

A toilet block is available by the car park. It is open before 9am and clean.

When it comes to parkbreakfast, there is a charming little cafe not far from the finish funnel with plenty of outdoor tables to enjoy good weather days. They offer pretty good pastries, but selection for sweets and cakes is minimal.

As a competitor to the McDonald’s index, I am continuing to collect data for the parkbreakfast index: how much is breakfast at each location?

At Aldenham parkrun, I ordered a pre-packaged brownie, a diet coke and a single espresso. This cost me £8.6. Pretty expensive considering what it was. Mostly paying for location, I guess.

Aldenham parkrun: Video Highlights

As usual, I’ve taken a few video snippets during the run to give an idea of the course. If you like it, please subscribe, it’s a fun past time for me 🙂

The other parkrun videos on my YouTube channel are all linked on the course review and video highlights summary page.

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Achievements and performance

Conclusions

This was a very nice surprise. I really enjoyed the venue and the course and it was not as awfully hot as it could have been given the heatwave. It is a fun course and it can be a PB one, if it is not muddy.

I would love to come back and who knows, maybe something in the future will bring me to the area once again.

Finally, obviously, thank you, Aldenham parkrun team for your hospitality!