SpaceX's HangarX is the main refubirshment facility for its Falcon 9 first stages and payload fairings, routinely recovered after most missions & reflown on subsequent flights.
Pad 39A serves as one of SpaceX's two launch pads at the Cape, with rocket stages regularly shuffling between here, HangarX, Pad 40 and Port Canaveral.
Three rockets composed of five first stages can be seen in the image below, with a Falcon Heavy shortly before flight in the distance:
Launch Photography by Ben Cooper | Read Copyright Notice