With this Minecraft 1.16.5/1.15.2 seed, you have to start the game on a beautiful mushroom island, on which there are a huge number of mineshafts. From the start you will have a sufficient supply of food and the opportunity to find valuable loot.
There are no open passages to mineshafts, but the tunnels are not deep from the ground, so you can dig in any convenient place. You will get to them anyway.
Screenshots:
Seed Showcase:
Seed Code
For Minecraft 1.15.2 to 1.16.5:399942533753735804