Ultima II: The Revenge of the Enchantress/Pangea age

OPTIONAL: dungeons and towers

 * In 1423 BC, in Castle British, the subdued balron whimpers: Lithium packs the 16th level!

Tri-lithium is required to travel in space in 2112 A.D. All the chests on floor 15 in any dungeon and tower contain tri-lithium only. In the original version of Ultima 2, dungeons and towers are completely optional, because tri-lithium can also be dropped by defeated thieves.

In the Japan-only FM-Towns port, enemies do not drop tri-lithium anymore, therefore there is a reason for exploring dungeons and towers. Still, 20 tri-lithiums are sufficient to visit all the planets and come back to Earth; so, exploring one tower on Earth is really all you need.

Remember that collecting 100 tri-lithiums is the same as collecting zero, because of the 99-rollover mechanic.

Most chests contain gold. Some contain a random weapon or armor.

Some considerations:
 * Floors 0-1: the only enemies are orcs; if there is a significant amount of chests, exploration can be worth it (e.g. the tower in 1990 A.D.).
 * Floor 2 onwards: the presence of ghosts requires a large stock of torches; venture here if you have more than 90 torches and you want to use up some.
 * Floor 8 onwards: the presence of gremlins requires a very large stock of food; no need to get this deep in dungeons and towers.

The table below is subdivided in two sides: on the left, dungeons and towers on the Earth, on the right, dungeons and tower in the solar system.

Dungeon in Greenland
In the DOS version of Ultima 2, this dungeon cannot be accessed in Pangea. This dungeon is definitely not worth exploring, unless you need to use up some torches and tools.
 * Treasure chests on floors 0-1: 2
 * Total treasure chests: 11
 * Tri-lithiums: 8

Tower in 1423 B.C.
This tower is between a swamp and a forest, therefore the safest way to get there is by ship. Exploring this tower is more rewarding than the Greenland dungeon, but still less rewarding than the Tower in 1990 A.D.
 * Treasure chests on floors 0-1: 0
 * Total treasure chests: 46
 * Tri-lithiums: 31