Interior view of the Basilica Cistern in Constantinople, Asia Minor. The underground cistern was constructed under East Roman Emperor <a href="//commons.wikimedia.org/wiki/Justinian_I" class="mw-redirect" title="Justinian I">Justinian I</a> (r. 527-565) as water reservoir.
<a href="//commons.wikimedia.org/wiki/User:Gun_Powder_Ma" title="User:Gun Powder Ma">Gun Powder Ma</a>
<span class="int-own-work" lang="en">Own work</span>