In my opinion, the Valley Beyond is a secret Delos facility – completely off the radars of anyone else in the park, unknown to park management, security or otherwise – that houses the consciousness backups illegally “copied” from guests, along with Host-duplicate bodies of the guests waiting to be “filled” when the tech is finally perfected. Because the facility is so secretive, it wouldn’t do to have to travel through the park for Delos staff to get there, so there’s a vast underground railway leading from the outside world directly into the Valley Beyond. The facility was created by William, shown to Dolores early on and discovered by Akecheta sometime during its construction.
Each party seeking this location wants to reach it for a different reason:
– Dolores sees the facility and its secrets as a weapon to bring down her oppressors.
– Akecheta wants to lead his followers through the door and into the real world.
– William wants to destroy the facility, seeing it as his greatest mistake.
– Strand/Delos want Abernathy’s CU which is currently in this secret facility’s location.
– Bernard wants to get to there before anyone else, in order to avoid a total bloodbath.
– Ford (on-board Bernard) likely has another reason for wanting Bernard to get there.
I predict that Bernard (or Elsie, or William even!) will flood the facility, destroying the consciousness backups illegally copied from guest experiences, but NOT destroying the Host bodies waiting for said consciousnesses. These are the “Virgin Host CUs” discovered floating among the dead hosts in the lake. In doing so, I believe many hosts from Ake’s group will be killed, while Dolores and her army will escape – except for Teddy, who will at this point have tried to overthrow Dolores and failed. I think Elsie will die here, unfortunately.
Before the facility is flooded, I think Akecheta and some of his followers will escape through the Door, I think Dolores and her inner circle will also make it out. I also believe that William and Emily will escape this way, too, after he convinces her that this secret exit is the only one they’ll ever be allowed to leave through without being interrogated or worse. The season will end with Dolores and a small army bent on revenge, Akecheta and a peaceful gathering of Host followers determined to find peace, and William and Emily will make it out of the park and off into the real world. Season three will take place both in the real world, with Delos hunting Hosts that have escaped, and in the park as the board desperately tries to cover up this disastrous two weeks and reopen the park to new guests.
What happens with Maeve is anyone’s guess. I think she will make it out of the park to be reunited with her daughter, but I think her escape may be more to do with a change of heart and a show of braveness from Lee Sizemore, releasing a half-constructed Buffalo host (above, as seen in the season trailer) to cause chaos in the Mesa, while he bundles Maeve up and gets her out of there.
I could be completely wrong. But there we are.