I don't think that they "found" one, but maybe they did, they probally built a device to hold a wormhole and open it in a safe location. Then when
they arrived they built another one to go to other worlds.
What I'm syaing is with 1 Device you can go anywhere, but once you get their you must build or use another to get back/to another world.
If it is indeed possible we'd have heard about it by now for sure, they'd keep it secret, but think how deadly it could be used in wars:
eg:
Russia build one and send nukes through to the US one, US retaliate by sending nukes back, maybe for our own safety they're keeping them secret.
And if they do exist, then someone should be able to build another backed by private funding!








