How do you go underground in Animal Crossing?

Answer 1

You can't go underground, at least in Animal Crossing and Animal Crossing Wild World. In Animal Crossing City folk, in the city, a random day after 8 o' clock at night, the cones on the right side will be knocked down, on a random night, and you could go see resseti, but that's as close to underground as you can get.

Answer 2

Yes it is..but it comes on nights usually on a specific day but I didnt check the day when it did. It is resetti`s sweeter brother and he will give you a golden shovel and a silver shovel. You can tell because when you go to the city on the right side walk all the way down and a big golden light will be on. walk in and he will say stuff like "Why are you in here go go go im working. " and then he will say yiu not leaving huh my little dear? then you blush and he will give you the shovels. after you receive those he wont come anymore