Despite rumors, no traces of secret underground facilities have been found.

During the relocation to our secret facility some of the lab materials were lost.

We were headed deep into the jungle to the secret facility hidden there.

Even assuming there isn't some other secret facility we haven't found yet, what other reason do they have?

He was therefore kept in a secret medical facility, isolated from the world so that the cover-up would not be discovered.

After he returned to government, a secret nuclear facility was built near Dimona.

Rather, they come from a secret facility built into the base of the hill.

We already know where the material was stolen from a top secret European facility.

"It goes to a secret facility within the hotel that is being used by one of our intelligence agencies."

I'm told there's a secret facility carrying out research for that project.