The interior of the castellum aquae in <a href="//commons.wikimedia.org/wiki/Pompeii" class="mw-redirect" title="Pompeii">Pompeii</a>. We are looking into the spur aqueduct off the <a href="https://en.wikipedia.org/wiki/Aqua_Augusta_(Naples)" class="extiw" title="en:Aqua Augusta (Naples)">Aqua Augusta</a>. About 50 metres further on there is an access to the aqueduct—hence the light in the distance.
The aqueduct is about 1.5 metres high so it is quite credible that Attilius and Corelia could have escaped through it as in Robert Harris' novel <i><a href="https://en.wikipedia.org/wiki/Pompeii_(novel)" class="extiw" title="en:Pompeii (novel)">Pompeii</a></i>.
<a href="//commons.wikimedia.org/wiki/User:RHaworth" title="User:RHaworth">RHaworth</a>
CC BY 2.5
<span class="int-own-work" lang="en">Own work</span>