Floating cities

The term Floating Cities can refer to one of two types of locations.

Atmospheric Floating Cities
Atmospheric Floating Cities are large structures that with a combination of Arti Grav and buoyant gases, maintain themselves at a certain distance from the center of the planet. While the vast majority of the Atmospheric Floating Cities are located in the atmosphere of Jovian planets, a small percentage are located on rocky planets.

Their size varies from under 50,000 beings to over 2,000,000.

"Aquatic" Floating Cities
Aquatic Floating Cities are located on the surface of large liquid bodies. While in many cases the liquid in question is water, that is not always the case with the Ammonia lakes of Titan normally cited as an example.

A the time of the Ascent there were three cities on Terra.