This a railway yard. Clearly visible is the turntable (the contraption to change the direction of old steam locomotives).
The City of Cologne was bombed in 262 separate air raids by the Allies during World War II, including 31 times by the Royal Air Force (RAF). Air raid alarms went off in the winter/spring of 1940 as enemy bombers passed overhead. However, the first actual bombing took place on 12 May 1940. The most notable attack on Cologne was the first Allied 1,000 bomber raid on 30 May/31 May 1942.
Another view of the rail yard.
Bridge broken across the river Rhine
Another view of the bridge broken
The Allied bombers faced a lot of flak, literally.
The cathedral. Bombed out.