a mine entrance for the abandoned mine shaft

Well the mine shafts in Minecraft are cool and useful but where do they lead? There should be a big mineshaft entrance to make it more realistic. In Minecraft as of right now, are not very realistic. the mines themselves are great but they need more to it than a little mine 100 blocks down not leading anywhere. I have seen mine shafts that are only around 20-30 blocks long and have no exits or entrances. It would be a lot easier and people would like it a lot.