I voted for
Nazca Lines: Required: Mysticism - could provide some culture points/turn (cause of huge, artistic and geometrical 'paintings'), some +happy faces (gathering of masses of people during the walkabout-processions of the 'paintings') and a negative bonus of - hammers as well cause all the small stones had to be removed to carve out the kilometers of blank lines, lot of work, always new lines to be done. I suggest Nazca ist no expensive wonder to be built, but it has to get more expansive by -hammers/turn over time. Obsolete after machinery?! GPP: +2/turn Priest
Templo Mayor: Whipping gives 33% more hammers + a good amount of culture points/turn; mathematics needed to build; expansive; stone required for double production; obsolete with liberalism GPP: +1/turn Engineer +1/turn Scientist
Tower of Babel: Required: Writing; effects: +4 Population, +2 Trade routes; expansive; trade route bonus obsoletes with Engeneering; GPP: +2/turn Merchant
Trans-Siberian Railway/Trans-Pacific Railroad: Required: Railroad; effects: railroad tiles on desert, tundra produce +3 gold, railroad on forrest +2 gold (making lumbermills and f. preserves more attractive); double production speed if gov=state property; GPP: +2 Engineer