[css] How do I position an image at the bottom of div?

I want an html image to be flush with the bottom of a div tag. I can't seem to find a way to accomplish this.

Here is my HTML:

<div class="span8">
  <img src="/img/play-shot1.jpg" class="text-center shadow">
</div>

The problem is that the div is nested within other divs that have padding or margins.

Using flexbox:

HTML:

<div class="wrapper">
    <img src="pikachu.gif"/>
</div>

CSS:

.wrapper {
    height: 300px;
    width: 300px;
    display: flex;
    align-items: flex-end;
}

As requested in some comments on another answer, the image can also be horizontally centred with justify-content: center;

< img style="vertical-align: bottom" src="blah.png" >

Works for me. Inside a parallax div as well.