Spawn in the plain biome. In this seed have mineshafts out in the open it very rare because the mineshafts never displayed out in the open in a plains biome. Exceptions the mineshaft very close a mesa biome. However this mineshaft towards opposite direction of the mesa biome then we can consider it is lying on plain biome. After explore the mineshaft you can decide to explore the mesa biome you will see some multiple mountain islands and great lake.
Seeds : 37330 Work in PE ver0.10.5 or ver0.11.0+