Dr. Finkelsteins Lab is one of two “hidden” locations on Fantage. The Lab houses “poison” which is required to be found in some events. To get there begin by going to The Island.

Click the three posts in the order the sign shows. (The sign above my head. In this case you would click diamond, then star, then circle.)
A bush will slide away revealing secret elevator. Click the the elevator to ride below ground.
And BOOM you’re there.

There’s nothing functional in the room unless there is an event there, however it’s a nice spot to hide. Have fun!