Back in the mid to late 70’s I saw a movie about a group of explorers looking for a lost city or temple in possibly central America. It was in English and in color.
The only scene that really stands out for me is where the explorers are in a cavern (or mine, or maybe an underground temple) when they come across an open heavy stone door. For some reason they move the door a bit to find the skeletal remains of a previous explorer crushed to death behind it. I’m pretty sure it was a person they knew who disappeared years ago.