the banks can be found in all the major cities (Lion’s Arch, The Grove, etc). Look for a black bag inside a gold coin icon on the map in the town. You can also access your account bank from any crafting station (also in towns, and found somewhere in the starting zones for each race). Alternately, you can click on the little tower icon in the upper left corner of your screen, travel to World vs. World and look for the crafting stations there. To go back to where you were before from WvW, go to the character selection screen and log back in.
