Hertfordshire Half Marathon & 10k November 2025

Hertfordshire Half Marathon & 10k In Support of Garden House Hospice Care on Sunday 2nd November 2025!

This popular ROAD CLOSED half marathon starts and finishes in front of the iconic Knebworth House with the course taking participants around the beautiful surrounding rural roads.

Knebworth House is a grade II listed house set in acres of beautiful gardens and parkland. Knebworth House has welcomed many music artists for major open air concerts, including Robbie Williams, Oasis, Led Zeppelin and Red Hot Chilli Peppers. The grounds are home to popular tourist attractions including an adventure playground and dinosaur trail.

Race Distance & Start Times 

09:00 am - Half Marathon

09:30 am - 10k

Included in the entry

With RunThrough you can expect a friendly team of marshals to help guide you round the course and cheer you on to the finish, a lively and well-serviced event village with plenty of food and drink options including free goodies from our partners at the finish line after your hard effort.

We have been extensively researching what runners consider important, and sustainability is fast becoming the top issue. Click here to see what RunThrough is doing for sustainability.

T-Shirts at events have become a hot topic with concerns around the quality not being high enough to wear on a regular basis. We have decided to tackle this by offering a RunThrough Kit Technical T-Shirt with a retail value of £22 for £12 with the addition of the Hertfordshire logo printed on the chest.

We can do this with our partner RT Kit as part o