Is it possible to Train Yourself to have a Better Memory? Some way to "exercise" those parts of the brain?

I have always had a poor memory, both short term and long term. And that does affect how well I can do in classes that require memorization; and in many parts of normal life.

So, I am wondering if there is a way to exercise, or train the mind to have a "stronger" memory. I don't mean using tricks and tools as a way of remembering things. I'd like to get better memory "muscles", like the stronger faster muscles that one can get with physical exercise.

Or is that not really possible?

Thanks!