An underground substation is an electrical substation that is constructed entirely or primarily below ground level. While conventional substations require large plots of land, underground versions are designed to operate in dense urban environments where space is limited and real estate is prohibitively expensive. They are often placed beneath parks, city squares, or even inside multi-story car parks.

The primary reasons for using an underground substation include:

• Aesthetics: They are essentially invisible, preserving the visual landscape and blending into the urban environment.

• Space Saving: The surface area can be used for other purposes, such as commercial buildings or public green spaces.

• Enhanced Reliability: They are highly resistant to damage from severe weather, vandalism, and other external factors that can affect an above-ground installation.