The Emperor's Tomb is a monument given as a reward for completing the Wealth Task. Like all monuments, it can only be built once per game, and provides 3 population and 400 score to the city it's in.
The task is activated when you research Trade. To complete it, one must have 100 resources accumulated at once. It is not cumulative. If you complete the task, but then spend some resources before placing the Tomb, you will still have completed the task.
The Emperor's Tomb is almost always a square-based pyramid. Kickoo's Tomb is a pile of stones in the shape of a pyramid.
|Altar of Peace, Emperor's Tomb, Eye of God, Gate of Power, Grand Bazaar, Park of Fortune, Tower of Wisdom|