I need to add an element *somewhere* within, or directly before/after, the main menu block. For example, the generated HTML should be something like this:

```
<div id="main-navigation">
  <div class="block block-system" id="block-system-main-menu">
    <div class="block-inner clearfix">
      <div class="content clearfix">
        <ul class="menu">
          <li class="first expanded">
            <a href="">About</a>
            <ul class="menu">
              <li class="first leaf">
                <a href="">General Info</a>
              </li>
              <li class="leaf"><a href="">Video</a></li>
                <!-- ... other menu items -->
            </ul>
          </li>
        </ul> <!-- this ends the top level main ul.menu -->
        <!-- a div added here would be ok -->
      </div>
    </div>
  </div>
</div>
<!-- or a div added here would be ok -->

```

I am currently trying [`hook_block_view_alter()`](https://api.drupal.org/api/drupal/modules%21block%21block.api.php/function/hook_block_view_alter/7) and have tried multiple variations of something like this:

```
function theme_block_view_alter(&$data, $block) {
  if ($block->delta == 'main-menu'
    && $block->region == 'menu') {
    $data['content'][] = array(
      '#markup' => '<div class="."><a href="#top">Close Mobile Menu</a></div>'
    );
  }
}

```

which is the closest I have come. This adds the div within `ul.menu` (top level) after the last `li` element; that won't work.

I can't seem to find a theming function for the menu as a whole, just `theme_menu_links()`. I see the theme wrapper `menu_tree__main_menu` within `$data` in `hook_block_view_alter()`, but I don't see a file or function that resembles that.

I'm aware that there may be a much better solution that I'm just not thinking of, so I'll state the final goal:

1. Absolute positioned menu. (I can work with `#main-navigation` being absolute and the element coming after it **or** with `ul.menu` being positioned, and the element coming after it.)
2. A link that follows the menu in markup, but is outside of the absolute positioned menu, so that I can position relative to window, not the `ul`.

Thanks!