A box full of sand, at Pearson International (YUL).
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/50642338@N00">Simon Law</a> from Montréal, QC, Canada
CC BY-SA 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/sfllaw/509103377/">Sandbox</a>