Urza's
Urza's is a nonbasic land type originally created for the Urzatron lands in the 8th Edition rules update when all land types were cleaned up.[1]
Urza's Power Plant, Urza's Mine, and Urza's Tower from Antiquities were joined by Urza's Factory when Time Spiral was printed. The latter is the only card to have Urza's as its sole land type.
In the older rules the Urzatron cards referred to each other by their name, not by their type.
Mine
Mine is a nonbasic land type created for Urza's Mine in the Eighth Edition rules update when all land types were cleaned up.[2] In the older rules the Urzatron cards referred to each other by their name, not by their type.
A mine is an excavation made in the earth for the purpose of extracting ores, coal, precious stones, etc.
Power-Plant
Power-Plant is a nonbasic land type created for Urza's Power Plant in the Eighth Edition rules update when all land types were cleaned up.[3] In the older rules the Urzatron cards referred to each other by their name, not by their type.
A power-plant is the equipment, including the fixtures, machinery, tools, etc., and the buildings necessary for the generation of power, as electric or nuclear power.
Tower
Tower is a nonbasic land type created for Urza's Tower in the Eighth Edition rules update when all land types were cleaned up.[4] In the older rules the Urzatron cards referred to each other by their name, not by their type.
A tower is a building or structure high in proportion to its lateral dimensions, either isolated or forming part of a building.