Maybe secret experiments were carried on here - and given up afterwards.

So far, panel officials say, they have uncovered evidence of hundreds of secret experiments on people.

Many of them performed secret experiments on the populations they oversaw.

Are there not perhaps some so classified and secret experiments hiding behind national security?

"Eddie and I are conducting a secret scientific experiment in our secret place."

Before she can do that, Serizawa tells her about his secret experiment.

Suppose Logan made one last secret experiment - and succeeded!

This would seen an ideal place to conduct secret experiments or research, sir.

The Kaer'n were born millennia ago as part of a secret experiment.

It was later revealed to have held three young superhumans who were the subjects of secret experiments.