A <a href="https://en.wikipedia.org/wiki/letter_box" class="extiw" title="en:letter box">letter box</a> with the number 6633 in <a href="https://en.wikipedia.org/wiki/Montreal" class="extiw" title="en:Montreal">Montreal</a>, Quebec, Canada.
<a href="//commons.wikimedia.org/wiki/User:0x010C" title="User:0x010C">0x010C</a>
CC BY-SA 4.0
<span class="int-own-work" lang="en">Own work</span>