An 1875 photograph of a family dressed in finery enjoying a day out at Stonehenge may be the earliest such snap taken at the monument.
English Heritage asked people to send in their pictures to mark 100 years of public ownership of the stones.
After sifting through more than 1,000 images historians said they believed the photograph of Isabel, Maud and Robert Routh was the oldest.
It will be part of a new exhibition of personal photos titled Your Stonehenge.
One picture shows the group sitting on the stones – which would now only be allowed on special occasions – with a picnic rug and what appears to be a bottle of Champagne.
In another, some of them are in a horse-drawn carriage.
“They’re wearing fashionable outfits and hats,” said English Heritage historian Susan Greaney.
“Right up until the 1920s and ’30s people did dress up for days out like this, in their Sunday best, suits and hats.”
The exhibition shows how photography has changed – illustrated by “the way that people pose” and how “their faces have got closer to the camera until they are taking a picture of themselves more than they are of Stonehenge”, said Ms Greaney.
English Heritage is now asking people to get in touch if they know of an earlier family snap at Stonehenge.
The earliest known photograph of Stonehenge, not featuring a family, is thought to date from 1853 – 22 years earlier.
The most recent photo in the exhibition was taken by renowned photographer and guest curator of the exhibition, Martin Parr, at the 2019 Autumn Equinox.
It features an unknown couple kissing while taking a selfie against the backdrop of the stones.
Mr Parr chose 10 of the images in the exhibition and said he hoped to track down the couple in his picture.
He said the photographs people sent in “really show what the stones mean to people and how our relationship with a site like Stonehenge has changed and yet stayed the same through time”.
Your Stonehenge – 150 years of personal photos runs from 12 December to late August 2020.