It was sometime between 2007-2014 I saw this (colored) film, and I only remember very few details.
It was about a young guy (between 15-25), who went into a cave. Inside, there was a shape of a hand craved into the wall of the cave. He put his hand there, and that made him travel back in time.
I don't know how far he went back, but I know that he found an old man, with grey hair. He brought him back to the present. I remember there was a scene when the old man looked up at the sky, and saw a strange bird. The young guy told him it was a plane.
I have already read Wikipedia's List of time travel works of fiction, without success.