Mundane by their very nature, manhole covers don't necessarily stand out to us while we walk or drive over them (although sometimes their simplistic appearance leads to interesting urban art). On occasion though, municipalities and even private property owners see the value of using the manhole cover as a unique way to help establish the identity of its surroundings.
Turns out we're not the only ones who are intrigued by the possibilities these underfoot pieces of infrastructure provide: there's even a Flickr pool with over 14,000 entries of manholes from around the world. Below are 24 that caught our attention:
Top image courtesy Flickr user Gilgongo under a Creative Commons license.