The current largest iceberg, A-23A, is currently spinning in place on top of an underwater mountain:

After leaving Antarctic waters, the iceberg got stuck in a vortex over a seamount, or an underwater mountain. Imagine a piece of ice about 1,500 square miles in area and as deep as the Empire State Building spinning slowly but steadily enough to fully rotate it on its head over the course of about 24 days.

- Tumin, R. (2024, August 7). After breaking free, world’s largest iceberg is stuck spinning in circlesNew York Times.