make it 30X30, doesnt mater, if its your first cave, yuor more than likely to **** up
![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
, just test about ,see how well you can make a cave using different walls. Dependin on ones you use, depends on size, ones liek PSC are huge, so you can make nice big maps, where as OC ones are smaller, so it would take twice aslong, then thiers complex, and non complex joins.