Mineshaft

Abandoned Mine Shafts are a new type of structure that will be added in Beta 1.8, along with strongholds. They are made up of blocks such as minecart tracks, wooden planks, torches, and cobwebs. Cave Spiders are exclusive to these areas. There are chests spread throughout the mine that contain things such as gold and iron ingots, ores, food or seeds. They can even contain diamonds or pickaxes and may sometimes spawn in air as a world generation glitch. Cave Spider spawners can also be found, and are coated completely in Webs, filling large parts of the air around it. These dungeons can be extremely large and have more than one dungeon connected to it. It is also possible but rare to have it spawn in a ocean so the Abandoned Mine Shaft is flooded. Abandoned Mine Shafts are also rich with ores such as Iron, Gold, and rarely Lapis Lazuli and/or Diamonds. As the 'shafts' are made of wooden planks, Abandoned Mine Shafts actually in turn provide very good source of wood while prospecting underground.

Obtainable items:
 * Diamond
 * Coal
 * Lapis Lazuli
 * Iron Ingot
 * Gold Ingot
 * Melon seeds
 * Pumpkin Seeds
 * Bread
 * Rails
 * Iron Pickaxe

Abandoned Mineshafts may be large, and may be akin to labyrinths during exploration, making it difficult to keep bearings. The poisonous Cave Spiders are very common and make exploration dangerous unless prepared.

Minecart tracks may be generated floating in the air from a world generation glitch. These tracks behave similarly to floating snow in that all adjacent glitched blocks will pop out when one is mined.