The inside view of a concrete mixer.<br>Round and round
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/35034360669@N01">Tom Chambers</a> from Castle Donington, England
CC BY 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/35034360669@N01/8188509">Flickr</a>