The Rocket Tower is an extra-terrestrial version of the Estuary Tower, and is designed for use in space, or on planets other than Earth. The main body is pressure sealed, and has facilities for docking with spaceships, and replaces the barge with A-pods and engines, allowing the fortress to move at a slow speed. These are not found on Earth due to the large size of the engines required to move in one g gravity. They are more common on Mars, the Moon, and on various moons through the solar system.
These towers aren't all designed for military operations, many are used for scientific and exploration purposes, as mobile bases, and can carry useful equipment such as industrial and excavation mecha, cranes, drone control centers, and crew quarters. Go to Comment
Replace the rocket engines, or submersible section with an interior chamber for a resident sorcerer to teleport the tower from a resting place to where it needs to be deployed. Central 'control' room houses the magic dingus crystal that powers it, and the tower does the magicking, but has to have a human pilot to mentally envision the destination.
I think non-magical versions of these towers in medieval / pseudo-fantasy campaigns would be cool too. People having to pump water in and out manually, then drag the towers with boats and or via chains pulled by horse teams on either side of the river to get them in the right place. Go to Comment