Places can now be booked on the Sarsen Trail and Neolithic Marathon on Sunday, May 4.
As well as being aimed at serious runners, walkers and cyclists, it is also a fun day for families wanting to enjoy the countryside and raise money for Wiltshire Wildlife Trust.
The event includes a full and half marathon and walks of seven, 11, 15 and 26 miles.
There will be two new bike routes of either a 30 or 50km multi-terrain, circular mountain bike route, starting and ending at Stonehenge.
The new cycling routes go through Salisbury Plain allowing cyclists to enjoy the unique landscape.
Money raised from the event supports the conservation work of Wiltshire Wildlife Trust, developing a sustainable future for wildlife and people.
Sarsen Trail co-ordinator Derek Gard said: “This is a rare opportunity for people to access an area which is usually closed to the public and to enjoy this spectacular landscape.
"I am also pleased to say that we have been given permission to take this year’s cycling route through Salisbury Plain.
"Almost 2,500 people took part last year and I expect this year will be equally popular.
"Marathon places are limited, so I urge people to sign on as soon as possible. This year, we are delighted to thank Mini Plant Swindon for their support.”
Theres is a mixture of grassland and farm tracks stretching across stunning landscape from the Vale of Pewsey, through the Avon Valley and across the wilds of Salisbury Plain to be enjoyed while the northern half of the route from Avebury to Redhorn Hill is an area rich in wildlife.
There is a good chance of seeing skylarks, brown hares, sedge warblers and kingfishers. The route crosses fields and country lanes as well as a couple of busier roads and a railway line.
The route is fully stewarded with first aid cover and support vehicles and a free coach service is offered for walkers between the starting and finishing points.
The trust provides regular water and toilet stops with refreshments available along the route.
All participants who cross the finish line at Stonehenge receive free refreshments at the end, along with a medal awarded to all those who finish their chosen route.
Thanks to English Heritage those with medals will have the opportunity to enter the Stonehenge site for free for the rest of the day.
Entry fees cover the trust’s costs for organising the event and more funds can be raised for Wiltshire Wildlife Trust through individual sponsorship.
There is an early bird discount for those who register before March 7.
For further information email firstname.lastname@example.org.
Online booking is available at www.wiltshirewildlife.org