Manholes are an essential yet overlooked part of urban infrastructure. They provide access to the underground systems that are important for maintaining the flow of water, sewage, and electrical ...

Manhole covers are usually round. Most people probably don't spend their days thinking about why that is. But there's actually a cool geometry reason behind the design: Circle-shaped things can't fall ...

Wander down a busy street in any large city, and you'll likely see them: manholes. They're pretty ubiquitous, spaced at regular intervals along the road. Manholes, which are increasingly termed ...