A manhole is the top opening to an underground utility vault

Utility vault

A utility vault is an underground room providing access to subterranean public utility equipment, such as valves for water or natural gas pipes, or switchgear for electrical or telecommunications equipment....

 used to house an access point for making connections or performing maintenance on underground and buried public utility

Public utility

A public utility is an organization that maintains the infrastructure for a public service . Public utilities are subject to forms of public control and regulation ranging from local community-based groups to state-wide government monopolies...

 and other services including sewer

Sanitary sewer

A sanitary sewer is a separate underground carriage system specifically for transporting sewage from houses and commercial buildings to treatment or disposal. Sanitary sewers serving industrial areas also carry industrial wastewater...

s, telephone

Telephone

The telephone , colloquially referred to as a phone, is a telecommunications device that transmits and receives sounds, usually the human voice. Telephones are a point-to-point communication system whose most basic function is to allow two people separated by large distances to talk to each other...

, electricity

Electricity

Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...

, storm drain

Storm drain

A storm drain, storm sewer , stormwater drain or drainage well system or simply a drain or drain system is designed to drain excess rain and ground water from paved streets, parking lots, sidewalks, and roofs. Storm drains vary in design from small residential dry wells to large municipal systems...

s and gas

Natural gas

Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...

. It is protected by a manhole cover

Manhole cover

A manhole cover is a removable plate forming the lid over the opening of a manhole, to prevent anyone from falling in and to keep unauthorized persons out....

, also known as a 'biscuit', a plug designed to prevent accidental or unauthorized access to the manhole. Those plugs are usually made of metal or constructed from precast concrete

Precast concrete

By producing precast concrete in a controlled environment , the precast concrete is afforded the opportunity to properly cure and be closely monitored by plant employees. Utilizing a Precast Concrete system offers many potential advantages over site casting of concrete...

 (especially in Europe). Manholes are usually outfitted with metal or polypropylene

Polypropylene

Polypropylene , also known as polypropene, is a thermoplastic polymer used in a wide variety of applications including packaging, textiles , stationery, plastic parts and reusable containers of various types, laboratory equipment, loudspeakers, automotive components, and polymer banknotes...

 steps installed in the inner side of the wall to allow easy descent into the manhole.

Manholes are generally found in urban area

Urban area

An urban area is characterized by higher population density and vast human features in comparison to areas surrounding it. Urban areas may be cities, towns or conurbations, but the term is not commonly extended to rural settlements such as villages and hamlets.Urban areas are created and further...

s, in streets and occasionally under sidewalk

Sidewalk

A sidewalk, or pavement, footpath, footway, and sometimes platform, is a path along the side of a road. A sidewalk may accommodate moderate changes in grade and is normally separated from the vehicular section by a curb...

s. They are usually in circular shape to prevent accidental fall of the cover in the hole.

In rural

Rural

Rural areas or the country or countryside are areas that are not urbanized, though when large areas are described, country towns and smaller cities will be included. They have a low population density, and typically much of the land is devoted to agriculture...

 and undeveloped areas, services such as telephone and electricity are usually carried on utility poles or even pylon

Electricity pylon

A transmission tower is a tall structure, usually a steel lattice tower, used to support an overhead power line. They are used in high-voltage AC and DC systems, and come in a wide variety of shapes and sizes...

s rather than underground.

Hazards caused by stray voltage in manholes

In urban areas, stray voltage issues have become a significant concern for utilities. In 2004, Jodie S. Lane was electrocuted after stepping on a metal manhole cover, while walking her dog in New York City. One solution is the Electrified Cover Safeguard invention, which is an on site, real time stray voltage warning system which is being used in the street lights in New York City and is also being tested by ConEd

Consolidated Edison

Consolidated Edison, Inc. is one of the largest investor-owned energy companies in the United States, with approximately $14 billion in annual revenues and $36 billion in assets...

 and other utilities and municipalities in England, Europe, and Japan.

Feminist issue with manhole name

In 1990, the city of Sacramento, California

Sacramento, California

Sacramento is the capital city of the U.S. state of California and the county seat of Sacramento County. It is located at the confluence of the Sacramento River and the American River in the northern portion of California's expansive Central Valley. With a population of 466,488 at the 2010 census,...

officially renamed all its manholes to "maintenance holes" out of concern for gender equality. The name "maintenance hole" was selected because the term shares the same initials as the word "manhole", thereby eliminating the need to change the MH labels on the city's utility maps.