Manholes

Manhole covers stop people falling
into manholes.

They keep out other bad stuff too.

Most often they’re made of cast iron but occasionally with infills of concrete.

They can weigh more than fifty kilograms and their weight keeps them in place.

Manhole covers usually have a “pick hole” so they can be lifted with a hook or handle. (Other tools can be used too, including electromagnets.)

Manhole covers are inexpensive, strong, and heavy but, despite their weight, are sometimes stolen, usually for scrap.

Unfortunately, manhole covers are too large to be easily collectible.

Their ubiquity has led some people to collect pictures of them instead.