Or theater........and drive-in for that matter.
I'm guessing that, in my case, it was THE LAND THAT TIME FORGOT in 1975. I was born in 1970 so I would have been about 5 years old. Other ones that come close would be KING KONG (1976), STAR WARS and FORCE TEN FROM NAVARONE (1977). I also remember seeing one of those 'Benji' dog films around 1977 also.
Can you remember???