Mercury

Mercury is a planet of the Terran Solar System in Ultima II that can be visited with the rocket ship in the time of the Aftermath. Minax' meddling with the timestream had caused the planet to be quite different from its original state.

There however isn't much to see on this planet, apart from a dungeon and lots of swamps.

Mercury is on the space chart of the documentation, and its coordinates are 5,4,5.

Trivia

 * In reality, Mercury is a barren wasteland. It is frozen solid on the side that is facing away from the sun. On the side facing the sun it is so hot, that lead would melt without problem.