Falcon 9 flight 20 (also known as Orbcomm OG2 M2) was a Falcon 9 space launch that occurred on 22 December 2015 at 01:29 UTC (21 December, 8:29 pm local time). It was the first time that the first stage of an orbital rocket made a successful return and vertical landing.**

“The Falcon has landed” | Recap of Falcon 9 launch and landing (3.37min)

The 156 foot first-stage rocket made history back in December 2015 when it guided itself back onto solid ground at Cape Canaveral, Florida where it originally departed from. 

The mission which sent 11 Orbcomm communication satellites into space would mark the first time SpaceX completed a vertical first stage landing without the rocket tipping over, and bursting into flames.

August 20, 2015: SpaceX historic Falcon 9 booster placed outside of company headquarters in Hawthorne, CA as historic monument.
August 20, 2015: SpaceX historic Falcon 9 booster placed outside of company headquarters in Hawthorne, CA as historic monument.

In the summer of  2016, SpaceX positioned the Falcon 9 booster in an upright position on the intersection of Crenshaw Blvd. and Jack Northrop Ave., the southeast corner of SpaceX’s main building. 

The dominant structure towers over a neighboring multi-story parking garage and can be seen as far away as nearby Interstate 105 – closest freeway to SpaceX, Tesla’s Design Studio and the Los Angeles Supercharger (StreetView).2015

Though SpaceX has gone on to successfully land a total of six rockets after ascending into orbit, the Falcon 9 being placed as a historic monument outside of the Hawthorne headquarters was the company’s first big first step towards its goal of building reusable rockets.

* Source: https://www.teslarati.com/spacex-displays-falcon-9-monument-hawthorne/
** Source: ​https://en.wikipedia.org/wiki/Falcon_9_flight_20