Where is the 2nd mine HELP PLZ!!!!!!!!!!!!!!!!!!!?

To unlock the second mine, get to level 10 in the first mine, thus clearing it, and then go back to the mine at about 9 pm or after and you will trigger the 2nd mine unlocking, just like it did for the first.

*Note- If you are aiming at getting the legendary sword on level 255 of the second mine, make sure ALL your tools are upgraded to the Mystrile level, or you won't be able to get the sword.

To get the second mine, you must get to the tenth and last level of the first mine and kill the black chick by hammering or hoeing it a couple of times. I have not tried anything else, but you could try the sickle. Anyway, after doing so, go on with your life, until you feel like the time is right and then, at 8:00 PM - 10:00 PM or 6:00 AM - 8:00 AM, walk into the excavation site and there should be a cut scene similar to the one in which you found the first mine (you must have your hammer equipped in your red slot or in your inventory!!), and the second mine will be there. It has, unlike the first mine, 255 floors. In fact, to find any mine, you must have killed all animals on the bottom of the previous mine and enter the site at the times of which I specified, and a cut scene will appear. You must have your hammer equipped or in your inventory, and the mine will appear. There are four mines. There is a sword on the bottom of the second mine (you need to upgrade all of your tools to Mystrile level, yes, that includes the fishing rod, to get it!) that you can use to access the Super Field. Other than that, I have not found any use of the sword.