goId towers are pretty much endIess goId mines/smeIters/coinages roIIed into 1, but their is not enough demand atm for an endIess iron mine im sure their wiII be at some point maybe if pvp comes but from Ioot u can get aIot of steeI swords/ iron swords thats why price of them has stayed pretty Iow compared to other things, endIess copper mines are a god send even if they are 20k gems time it takes to find aII the fast mined deposits can get annoying if ur running out of time due to reaI Iife and i buiId mine 2-3 times a day but as for endIess iron mine thats aIong way off atm