Ladder set-up kit
The wooden ladder set-up kit recipe can be purchased from Nook's Cranny for 2,000 Bells or found from message bottles during Kapp'n's boat tour. The vine ladder set-up kit recipe can be found on vine/glowing moss islands during Kapp'n's boat tour or from the archipelago, while the iron and golden ladder set-up kit recipes can be obtained from any villagers.
The vine also acts similar to a ladder set-up kit.
To place down a ladder set-up kit, the player would need to be near a cliff on either their own island or an island from a Mystery Island Tour or Kapp'n's boat tour. The kit cannot be used on other player's islands. Once the kit is set up, the player can interact with the item to go up and go down. It's possible to set up a kit on a diagonal corner.
The player cannot climb if there is an object in the way, nor can they climb up the fourth tier of cliffs. Attempting to climb on a fourth tier cliff will give the player a message: "It's too dangerous to climb any higher."