Key locks key lock in windows doors at caravan parks

I’ve got to adult sons both with autism, and both runners ,

Finding a caravan holiday that has key locks on doors and windows is very hard ,as both boys are also runners ,

Does anyone know of a caravan park preferably in Devon or near to it that supply key locks

As it’s hard trying to get away even for a few days in the summer , as just can not relax knowing that doors or windows can be opened

Thank you

For the reasons you are having we had to use cottages instead of caravans as the fire exit has to be unlocked on the inside.

Can I ask where you went and did you find that cottages we’re a lot better