People going to Avebury for the Summer Solstice are being advised they will not be allowed to camp overnight in the National Trust visitor car park.
People are advised to travel to the Solstice using public transport
A enforcement notice has been served by Kennet District council which stops the trust tolerating the practice for stays at pagan ceremonies.
A planning application has been made to install a height barrier to prevent caravans and motorhomes gaining access.
It will prevent all high-sided vehicles entering the car park all year round.
Brendan McCarthy, regional director for the National Trust, said it regretted the decision but it was the only solution.
There will be a limited number of car parking spaces available at a charge (for vehicles under 2.1 m high) on the evening of Solstice itself, Wednesday 20 June.
There will be no additional car parking for people arriving in the days before and after Solstice evening itself.