We already know that, when Arrow returns for Season 4 this fall, Oliver Queen (Stephen Amell) will have a brand new costume. As it turns out, that isn't the only upgrade fans will get a look at this year, with Entertainment Weekly debuting a new concept art illustration of Arrow's new lair, dubbed "Arrow Bunker" by the show's writing staff. Executive producer Marc Guggenheim wouldn't reveal exactly where in Star City this new facility is located, but he did discuss why a new lair was built in the first place.

"In designing the new lair, we had to think in terms of the much larger group that Oliver has now surrounded himself with and how Team Arrow is a much bigger enterprise. One of the fun things about this lair is that as opposed to one big space, where everyone would congregate, it's now a much larger space divided up into smaller spaces. There is an area for Felicity [Emily Bett Rickards] to work, there is an area for Oliver to work out, and there is a garage. There are many different places we'll continue to discover over the course of the season that give you a sense that this thing is a bit bigger than we got used to in the first three years."

This image comes just a few days after it was confirmed that Matt Ryan will guest star as John Constantine, reprising his title role from the now-canceled NBC series Constantine. The actor will appear in the fifth Arrow Season 4 episode, entitled "Haunted", which will feature a resurrection of some kind, according to The CW president Mark Pedowitz. In the comics, John Constantine has expert knowledge of the Lazarus Pits, and it is believed that this episode will showcase Caity Lotz's deceased Black Canary character being reborn as the White Canary, before she joins the midseason spinoff DC's Legends of Tomorrow.

Other new casting additions this season include Neal McDonough as Season 4's main villain, Damien Darhk, alongside Alexander Calvert as Anarky, Echo Kellum as superhero Mister Terrific, Jimmy Akingbola as the villainous Baron Blitzkrieg, Jeri Ryan as Jessica Danforth, a new character that doesn't originate in the comics, and JR Bourne as Double Down. Another DC's Legends of Tomorrow, Hawkman (Falk Hentschel), will also first appear on Arrow before the midseason series airs.

Arrow's Season 4 premiere is set to air Wednesday, October 7 at 8 PM ET on The CW. With just under two months left until the show's return, there will surely be plenty of new photos and footage debuting in the days and weeks that follow, so stay tuned for more updates. In the meantime, check out Arrow's new lair in the concept art image below.