Civilization II/Wonders

Apollo Program
Launch of a spaceship into planet orbit. Astronauts return with pictures of the globe. Effect being whole map revealed

The Great Wall
Grants virtual City walls to every city of owners civ. Increasing defence.

Effect expires after discovery of Metallurgy

Magellan's Expedition
The construction of Magellan's Expedition allows all of one's own naval vessels to move 2 more spaces than listed in their description.