GriefingAndCrafting Minecraft 1.2 - 1.3.2 Seed
Seed Code: GriefingAndCrafting
X: 11 / Y: 75 / Z: 297
Let's start with the ordinary things. A river doing a loop here, an island with sugar reed in the middle.
X: -32 / Y: 67 / Z: 244
Some pretty cool rocks with exposed coal.
X: -18 / Y: 55 / Z: 221
And then it starts to get pretty interesting. Meet the cave. It has a lot of exposed iron and... a 1-block wide hole. However, inside that hole lies a huge ravine with some freaking LAVA RIVERS! And you can reach it without mining a single block (and without fall damage, for that matter).
X: -68 / Y: 69 / Z: 221
And to top it off, have an enormous cave system with an exposed dungeon.