Cradle Wonders + El Dorado, Solomon's Mines, Atlantis...

[Jeppetto]

I always found it odd that Solomon's Mines and El Dorado were Natural Wonders in Civ 5. I think Natural Wonders have much better identity as something not directly man-made. On the other hand these are things allegedly made by civilizations older than those being played and these vacant ruins are all that remains, so stumbling upon them is like stumbling upon Natural Wonders. They are like Ruins providing benefits, but more important than Goody-Hut ruins of Civ 5. And Civ Rev seems to have system representing that.

So thinking about how these two (minus Atlantis) would make for good idea of World Wonder, I realized perhaps making new category would be better?

The idea would be that just like the game decides where playable Civs start, it creates starting location (as far from playables as possible) for civilizations older than playables, leaving behind them only Cradle Wonder. They'd be impassable, unworkable, but settling adjacent to them would provide the city some benefit.

If Atlantis would join the show, some RTesque ability to settle into waters for Future Era would be required, and I am not sure If that's good idea, but it would be shame to miss on it.

Given their "not provingly made by [playable] men" nature, they could be though to be made by gods, thus focusing them on being mythical things, usually from modern novels - among them also Shangri-La, Buyan or its Indian counterpart etc...

Naturally, this would require No Cradles option since I fully understand If some people want to keep the game historical rid of fantasy places hardly provable to exist.

 

[Alexander's Hetaroi]

The 2010 board game version had these tiles and they were considered relics. Not the precise term for them not to mention relics are already a thing. I believe in Civ Rev they are referred to as artifacts as well which also exist.
As much as I like historical accuracy I wouldn't mind these and I think "Mythical Ruins" would be a great name for them.
They could give an inherit bonus for being the first to discover them and then another bonus if you settle near them like other Natural Wonders like you said. Atlantis would have to be different as it would probably have to be in the ocean, though maybe reachable if it can only spawn in coastal water.

 

[Sostratus]

I always found it odd that Solomon's Mines and El Dorado were Natural Wonders in Civ 5.

I'm not sure if it was originally intended that they leak into the base game. They came about when New World and Scramble for Africa scenarios debuted them. Bison resource also came into the game that way. I think you could even get the fountain of youth in regular games? I imagine they expanded the list of natural wonders in some file without realizing the base game would also be able to pick them.

 

[Alexander's Hetaroi]

I have an idea of how these "Mythical Ruins" could work:
Atlantis (spawns on coastal water): First to discover received free Eurekas for the Future Era techs. If it is in your territory you gain a boost in science every turn.
El Dorado (spawns in rainforest): First to discover receives 500 gold. If it is in your territory you gain a considerable amount of extra gold per turn.
Fountain of Youth (spawns near the source of a river): First to discover receives health. If it is in your territory all your units heal faster.
Shangri-La (spawns adjacent to many mountains): First to discover receives a diplomatic point. If it is in your territory you gain more diplomatic favor every turn.
King Solomon's Mine (spawns in desert): First to discover receives a free copy of any minable luxury resource. If it is in your territory mines on luxury resources acquire more god and amenities when controlled.

 

[TyrannusRex]

I think the Tower of Babel was in Civ 5 as well? If you found it, it could reveal every civ that has also found it--- or if you're the first, it could reveal every civ.
The Garden of Eden could... do... something. Probably a big Faith boost/ability to found religion/free fruit luxury and a Eureka.

 

[Jeppetto]

I think the Tower of Babel was in Civ 5 as well? If you found it, it could reveal every civ that has also found it--- or if you're the first, it could reveal every civ.
The Garden of Eden could... do... something. Probably a big Faith boost/ability to found religion/free fruit luxury and a Eureka.

I totally forgot about Tower of Babel, that would be good concept, too.
BTW according to Google it was Civ Revolution.