On which side of the human body is the heart located?

The heart is situated in the mediastinum, which is a space between the lungs in the approximate center of your chest behind your breastbone. The heart is actually located more to the left, though, and so the reason you'll feel it beat harder on the left side is because that's where it is.

There are, however, congenital birth defects in which the heart is found on the right side of the chest. This is a rare case and the average human will have his/her heart situated more toward the left.