Best way to nest lists?

Question

I need to achieve some tricky layout and it would require some similar markup like this:

<ul>

     <li class="active">
        <a href="#"><?=lang('nuestros-hoteles')?></a>
        <ul>
            <li>
                <ul>
                    <li>A
                        <ul>
                            <li><a href="#">1</a></li>
                            <li><a href="#">2</a></li>
                            <li><a href="#">3</a></li>
                        </ul>
                    </li>
                </ul>
                <ul>
                    <li>B
                        <ul>
                            <li><a href="#">1</a></li>
                        </ul>
                    </li>
                </ul>
                <ul>
                    <li>C
                        <ul>
                            <li><a href="#">1</a></li>
                            <li><a href="#">3</a></li>
                            <li><a href="#">3</a></li>
                        </ul>
                    </li>
                </ul>
            </li>
        </ul>
    </li>
    <li>...</li>
</ul>

Question is,

Would this be valid and or semantic?

Answer 1

Yes nested lists are perfectly valid, and your code looks like it would be perfectly valid. http://www.w3.org/wiki/HTML_lists#Nesting_lists