Sinkhole

A Sinkhole is the entrance to a Cave and can be found randomly in the world.You can change sinkholes none in the world settings,but don't say more,lots or less. Each Sinkhole leads to a new cave. When first discovered, the Sinkhole will be a Plugged Sinkhole and is covered with a jagged rubble mound. Mining the Plug reveals the hole with a rope going down into its depths while providing Flint and Rocks. It takes six hits from a Pickaxe to unplug it. Once unplugged, Batilisks will come out of the Sinkhole at dusk.

There have also been sightings of three or four sinkholes in a world. Plugged and open Sinkholes are marked on a map by a gray mound and a hole with a red arrow pointing downwards, respectively.

Trivia

 * Basalt found in previously generated worlds were actually placeholders for Sink Holes and were turned into Sinkholes when the Caves update was released.
 * Using DebugSpawn("basalt") will still spawn a basalt, which doesn't change into a Sinkhole, compared to DebugSpawn("cave_entrance"), which directly spawns a Sinkhole.
 * As of caves can be regen and time elapsed here,you can get unlimited resources and avoid