The Dungeon Master's Guide's brand new Bastion System has been previewed in a new video from Wizards of the Coast.
Characters can acquire a bastion at 5th-level. Each week, the bastion takes a turn, with actions including crafting, recruiting, research, trade, and more.
A bastion also contains a number of special facilties, starting with two at 5th-level up to 6 at 17th-level. These facilities include things like armories, workshops, laboratories, stables, menageries, and more. In total there are nearly thirty such facilities to choose from.