These are all buildings that were once part of Farrel Foundry/Corporation. The Wiki entry is short but details an interesting history. These empty buildings once housed a foundry and its support operations, employing thousands. It made bayonets and cannon barrels for the Union Army in the Civil War, produced complex machine parts for Navy ships' propulsion systems in WWII. The current company is owned by a German corporation and makes materials for the plastics industry. It has—100 employees.
The building in the background, part of the Farrel complex, is being rehabbed as the new home of the Ansonia police department.
These views look in at the back of the city block sized building complex, the front of which will be the police department. Just a part of the whole, across Main Street from the foundry complex.
Back view of a tiny section of another part of the Farrel complex, a multi-story building with a footprint that must have hundreds of thousands of square feet of floorspace. A couple years ago it sported giant signs (the plastic kind you now see strapped to billboards) promising that it would be turned into condominiums—but those signs are gone now.