Danton Black meets with Java in an alley in episode 1x02 “Fastest Man Alive”.
The Old Cot Factory
Wally heads to an industrial area to throw the last piece of the Philosopher's Stone into the speed force and Barry arrives too late to stop him in episode 3x15 “The Wrath of Savitar”.
Izzy Bowin calls out DeVoe in an attempt to stop him herself and the team rushes to rescue her in episode 4x14 “Subject 9”.
Ralph and Sherloque follow the mask lead to a chemical plant but learn that hundreds of workers across several facilities use the same masks in episode 5x04 “News Flash”.
John Loring's Warehouse
Sue saves Ralph after he is spotted taking photos of an arms deal and later the two of them infiltrate through the sewers to locate the ledger in episode 6x12 “A Girl Named Sue”.