Videos filmed by eyewitnesses show the white campervan on fire with thick clouds of smoke billowing into the car park.
Two fire crews from Ripon attended and extinguished the fire.
Firefighters remain at the scene, conducting investigations into the cause of the blaze.
A spokesperson for North Yorkshire Fire said: "We were called to the scene at 5.17pm to a campervan on fire.
"Two crews from Ripon attended and extinguished the fire. They remain at the scene.
"There were no reported injuries.
"The cause of the fire is not known at this stage."