Johnston Hall from Alumni Walk.   Johnston Hall was the headquarters building for RCAF No. 4 Wireless School and RCAF Station Guelph.   Many of the residential school buildings commandeered by the RCAF look a lot like Johnston Hall.
<a href="//commons.wikimedia.org/wiki/User:SteveTheAirman" title="User:SteveTheAirman">J. S. Bond</a>
<span class="int-own-work" lang="en">Own work</span>