Junkyards consist of a single building in front of a large fence. Behind it is a large scrap yard with multiple piles of debris and burnt-out cars. A large number of dumpsters are found here which can contain food and ammunition.
Occasionally, a Junkyard Dog may appear in the building. It is described as being more dangerous than other dogs, and the party will have the option to "get killed by the dog" or "leave it alone" (the former of which kills a party member). Presumably, a survivor with Friend of Dog perk is able to tame it.
With one character, the "get killed by dog" option is now "make him follow you." This character has top strength and fitness, and the rest is low or unknown. Not sure what stat is making it happen.
When speaking to the junkyard dog with another dog, it still says "get killed by the dog."
Junkyard with Car
A typical junkyard with a random vehicle parked in front of the facility. The keys to the car are found somewhere among the trash heaps and scrapped cars.
A secure junkyard contains a safe within the main building that can be cracked open by survivors with a high mechanical skill. Otherwise, players will need to find a combination code or key somewhere in the scrapyard out back.