Ninijutsu wrote:Pave the ground with stone first. Also you can't build anything within 30 tiles of a cave entrance.
50 tiles normally
you can count tiles with CTRL+L (click on cave entrance themn move mouse - window shows tile count) - then look where the closest spot is where you're able to dig
example from last world how a cave wall can look (southern CPs are on the first diggable spots)

as you can't pave next to cave wall you'll have to work with segments and extra CPs