Bryan McAllister’s personal reference notebook
July 30, 2026Short & citedBlog
Civic Viewpoint.
A quiet encyclopedia with a personal desk
Kept by Bryan McAllister — short guides, clear facts, and the Canadian angle when it matters.
Music Box • Geography

Caspian Sea

The Caspian Sea is the world’s largest inland body of water, located between Europe and Asia.

Updated July 30, 20261 min readCited sources

The Caspian Sea is the world’s largest inland body of water, sitting between Europe and Asia. It is often classed as a sea but also called the world’s largest lake because it is landlocked and has no natural outlet.

What it is

The Caspian Sea is an endorheic basin, meaning it has no outflow to the ocean. It lies east of the Caucasus Mountains and west of Central Asia. Its waters are saline, not fresh, and its surface sits about 28 metres below global sea level.

Key details

The sea covers about 371,000 km² and reaches a maximum depth of roughly 1,025 metres. Five countries share its borders: Azerbaijan, Iran, Kazakhstan, Russia, and Turkmenistan. Salinity varies, with fresher water in the north and saltier conditions elsewhere.

Why it matters

The Caspian Sea is a major source of petroleum and natural gas. It also supports valuable sturgeon fisheries and is known globally for black caviar. However, the sea is shrinking due to reduced river inflow and higher evaporation from climate change, affecting coastlines and ecosystems.

In short

  • Largest inland body of water on Earth.
  • Bordered by five countries: Azerbaijan, Iran, Kazakhstan, Russia, Turkmenistan.
  • Known for sturgeon, caviar, and oil and gas reserves.
  • A closed basin with no natural outflow.

Quick questions

Where is the Caspian Sea?
It lies between Europe and Asia, east of the Caucasus Mountains and west of Central Asia.
Is the Caspian Sea a lake or a sea?
It is commonly described as both: a sea in name, and the world's largest inland lake or enclosed body of water in geographic terms.
What is the Caspian Sea known for?
It is known for being the world's largest inland body of water, its sturgeon and caviar, and its oil and natural gas reserves.

Sources

  1. Wikipedia — https://en.wikipedia.org/wiki/Caspian_Sea
    Supports: General location, classification as inland body of water, and geographic context.
  2. Encyclopaedia Britannica — https://www.britannica.com/place/Caspian-Sea
    Supports: Bordering countries, inland body of water classification, salinity, and geographic position.
  3. Encyclopaedia Britannica — https://www.britannica.com/summary/Caspian-Sea
    Supports: Bordering countries, lack of outlet, and economic importance.
  4. NASA Earth Observatory — https://science.nasa.gov/earth/earth-observatory/caspian-sea-44253/
    Supports: Area, five-country border, and inland water body status.
  5. European Space Agency — https://www.esa.int/Applications/Observing_the_Earth/The_Caspian_Sea
    Supports: Maximum depth context, location, salinity, oil and gas resources, and water-level fluctuations.
  6. Britannica Kids — https://kids.britannica.com/students/article/Caspian-Sea/273550
    Supports: Location, borders, area, and caviar/sturgeon importance.