-8746688725947809914Semilla de Minecraft 1.2 - 1.3.2
This is a seed I found on Minecraft snapshot 12w41a but I believe it will work on 1.
Código de Semilla: -8746688725947809914
X: 423 / Y: 101 / Z: -280
Here not far from spawn, there is a huge Y shaped ravine with the top right part of the Y underground. There are also a couple of smaller branches that lead off here and there. This is in a Plains Biome.
X: 522 / Y: 113 / Z: -355
Here we have an absolutely amazing Extreme Hills Biome with many awesome hang overs and ledges. The screenshot doesn't capture much of the immense size of the hills.
X: 994 / Y: 111 / Z: 615
And finally, here is an extremely steep cliff face in a Forest Hills Biome! I thought this would be a great place to maybe build a house! If not on top then maybe in it or sticking out!