1.7.10 seed. Hole to enter ravine, where other ravines intersect, found about 5 different ravines, might be more. Some are small and some are big. Biome is Extreme Hills so there must be emerald ore. Becareful not to loose yourself, good luck!
Update: As I played, I found two dungeons! And there are way more than 5 ravines, as you mine, ravines just keep showing up. So far more than 10 ravines.
Seed Code: 6701227987434444409
Spawn points
X: -8 / Y: 64 / Z: 237
Locations
X: 58 / Y: 72 / Z: 286
Hole to enter ravine, just keep searching and you'll see more ravines intersecting.
More Minecraft 1.7.2 - 1.7.9 Seeds
Coolbeans
W.O.W. This is awesome!