Deep beneath the ocean’s surface, a “forgotten city” emerges from the depths. This so-called city consists of enormous columns and carbonate walls, formed by hydrothermal activity in the region. It’s all part of a 700-meter-long (2,300 feet) stretch of seafloor that scientists refer to as the Lost City Hydrothermal Field.
This remarkable series of seafloor formations was initially uncovered in 2000 and is believed to be at least 120,000 years old. The formation of the city was driven by the uplift of the Earth’s mantle in the region, where seawater has interacted with methane, hydrogen, and other dissolved gases.
The outcome is a visually captivating “forgotten city” that is unlike anything else seen on Earth. Yet, there’s more to this city than just its towering, rugged peaks. Concealed deep within the crevices of the walls and columns rising from the ocean are extensive communities of microbial life that thrive on the hydrocarbons present in the area.
These microorganisms do not require oxygen to survive, and the heat in the vicinity creates an environment rich in snails and crustaceans. Scientists estimate that the gases emitted from the various natural chimneys in the area can elevate the water temperature up to 40 degrees Celsius (104 degrees Fahrenheit).
Although awareness of the “forgotten city” has existed for over 25 years, researchers have only recently succeeded in retrieving some of the mantle rock from the region. They announced this recovery in 2024, estimating that a sample measuring 1,268 meters long has been collected to aid in understanding how life originated on Earth.
Many theorize that similar locations may exist, hydrothermal fields ascending from the ocean floor. Nevertheless, this remains the first of its kind to be discovered by researchers. Gaining insight into the lifeforms inhabiting it could provide valuable knowledge in our pursuit of identifying signs of life on other planets.
Some scientists believe it could serve as evidence of active ecosystems on other celestial bodies like Europa or Enceladus. It may even shed light on how life thrived on Mars in the past, prior to the weakening of its atmosphere.
