Over on the Call of Duty website (opens in new tab), the Verdansk Subway System is broken down in great detail. At the beginning of every Warzone match, the Metro system will have a number of stations open to explore, each of which can be plundered for a variety of weapons and armor items.
From there, you can fast-travel between platforms by simply hopping on a subway train with the rest of your squad. It isn't just a case of hopping from one subway station to another though, as you can either journey around the subway system in a clockwise or counter-clockwise direction.
It's worth noting that you won't be able to take a Metro train to a station that's inside the gas closing in on Verdansk. You also won't be able to kill, or be killed, while you're on the subway train - that'll have to wait until after you've disembarked the train, so be careful where you're travelling to!
Call of Duty: Warzone Season 6 launches later this month on September 29. The Verdansk Subway System isn't the only new feature of the season, because both Farah and Nikolai will also be joining the fight as two new Operators.
Looking further ahead, the undead could be making their way to Verdansk in the near future. A leaked audio recording recently revealed voice lines for a Zombies version of Warzone, detailing how the undead won't be affected by the enclosing gas.