Wonder Woman: Curse of the Underworld

Justice League:  The successor to both the Batman and Superman animated series.  It's unfortunate that it never really found its groove due to its massive ensemble cast.  There were simply too many characters to focus on.

Well, at least Justice League had better action and serious plots compared to the He-Man remake.

Play Curse of the Underworld @ Toonami: Lost Data
(Athens was originally made of wood, but the discovery of gold enabled the city to build great stone structures.)