Great photos Ben. Very interesting historical perspective.
Thinking the first Photo is where the 5th ave El joined the Myrtle ave El on its way to Saqnd street and Park Row in Manhattan.
The second Photo shows the former station at Atlantic on the Fifth ave El. The LIRR Flatbush Ave. Terminal is to the right. Its after 1940 and the Fifth Ave El is being removed including this station. The LIRR station in the photo is now gone, replaced by a new Building and a shopping Mall. WE are standing about where the Barclays center is , Home of the Brooklyn Nets.
The Third Photo is on the SeaBeach line. Its an early construction photo. and is where the seabeack crosses over the LIRR Bay Ridge Branch. I love that construction equipment in the photo, Steam Powered of course .
The Fourth Photo brings us back to the Fifth Ave El at a point where it leaves Flatbush Ave to Run South on Fifth Ave. I think the street feeding into Flatbush Ave which forms the triangle that the building sits on is Dean Street. This photo looks like its from Near the turn of the century.
The Last Photo is the Culver Terminal in Coney Island. This is where oen arrived to spend a day at the shore in Coney Island Hey day when it was New York's Resort by the sea.