Centurion Running

Hundred Hills 50km®

15 Mar 2025

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Course Records

Mark Darbyshire (M)



Anna Klucnika (F)



The Hundred Hills 50km is a beautiful 50km trail ultra through the heart of the Chiltern countryside. Our season opener, the race consists of two different 25km loops. It starts and finishes at 850 year old Stonor Park, providing a truly stunning backdrop to the event. With a 9 hour cut off the race is ideal for runners looking to take on their first ultra and those looking to take a step up to our longer events. But also for those looking to race fast, early in the year. The route takes in 4000ft of climb, visiting picturesque villages and ancient woodland while traversing some incredible trails. Back at Stonor there is the opportunity for friends and family to spectate, food and drink on site and is a fabulous day out for all.

As with all Centurion events, runners will be fully supported by 5 well stocked aid stations, full medical support and a marked course. Race held under full UK Athletics Permit granted through the TRA (Permit Number Pending).


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15 Mar 2025 09:00

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80% TRAIL, 20% ROAD

General Info


Entries for 2025 open at 1000 on Saturday 6th April 2024 and are available on a first come first served basis. There is no waiting list for this event.

Cut Offs

Runners must finish the course within a 9 hour time limit. There are additional cut offs on route which can be found in the aid station table

Start/ Finish Location

Registration, Race Start, Race Finish and Race HQ are at Stonor Park, Stonor, Henley-On-Thames, RG9 6HF.


The route is a beautiful but challenging 50km trail ultra through the heart of the Chiltern countryside. The route takes in 4000ft of climb, visiting picturesque villages and ancient woodland while traversing some incredible trails.

A map of the route and a downloadable GPX file can be found at the bottom of this page.


Medal to Finishers only. Runners can refuse a medal during registration, and have a tree planted instead. Runners may exchange a medal for a patch at the finish line.

Additional prizes will be awarded to First/ Second/ Third place Male and Female. 

Winners of each age category will also be awarded prizes: M40, M50, M60, M70 and F40, F50, F60, F70. 

Aid Stations

A full list of the aid stations including the relative cut off times can be found here. Aid stations will carry as a minimum: Water, Coke, Tailwind, Gu Gels, chocolate, sweets, sandwiches, nuts, lots of fruit, wraps and other sweet and savoury snacks. There will be hot food and drink available at the finish which is included in the entry fee for all runners.

Drop Bags/ Finish Line Bags

Parking for the race is at the start/ finish so all bags should be left in vehicles where possible. For runners arriving without a vehicle - Finish Line Bags may be deposited at registration, whereupon they will be stored in number order and accessible to runners at the end of the race. Bags should be clearly labelled with runners name and bib number. 

Course Markings

The course will be marked with Centurion Ribbons and Centurion marker arrows for the entire duration.


No pacers are permitted at any point on the route. 


No crews are permitted at any point on the route.


There will be a dedicated team of race medics available throughout the race including a static first aid team at the finish line and a minimum of one roving team out on course at all times. If you suffer an injury or accident that warrants direct medical attention, the medics will be on hand to provide you with exactly that. Contact numbers and full details of what to do in an emergency will be given to you in the pre race information packs and again at race registration. Due to the nature of the course ie. some remote and far from roads, the medics may take some time to reach you, or potentially be out of contact tending to other runners. In those instances you should contact the emergency services on 999 AS WELL AS the race medics. Full instructions on what to do in an emergency can be found in the infopacks. 


80% of the course is on trail. Trail shoes are advised. 

There will be kit checks during the race and at the finish. Runners must carry the following mandatory equipment at all times. A time penalty of one hour will be imposed for any item found to be missing at any point on course. Please refer to this page for explanations on the inclusion of the below items. 

There are many options regards kit for fulfilling these requirements and those of other events. We stock what we believe to be the best options at our online store available by clicking here under the Mandatory Gear Section. Please ask us if you have any questions.

    • Fully Charged Mobile Phone including the numbers for the Race Medic and Race Director (on the number you have given at registration)
    • Water Bottles/Bladder capable of carrying a minimum of 1 litre.
    • Survival Blanket: 1.4m x 2m minimum
    • Waterproof Jacket: Gore-tex or similar, minimum 10000mm+ & must have sealed seams. 
    • Whistle
    • Long sleeved base layer or fleece top - This must be carried separately from the start and kept dry, for use only in an emergency. Starting in 2 layers is not a substitute.
    • Cup - this must be in addition to your flasks or bladder.

The video below takes you through the mandatory gear for the race and gives some tips and advice on how to pack it.

Course Map

Download KML fileDownload GPX fileNote: you may need to right click and Save As to download these files