UFO crash site

The crashed UFO is an unmarked location in the Commonwealth in Fallout 4 just to the east by south-east of Oberland station. However, there won't be anything there until the UFO crash occurs.

When traveling around, the Sole Survivor may hear the sound of a crashing plane. The start of the event is a random encounter, and as such, the chances of it happening are random, although it would seem the player character has to be within a certain distance of the crash site for it to occur. A ship will then pass quickly by, overhead before crashing in the distance. Actually seeing the ship might be difficult because of how quickly it is moving but it does leave a short lived, but distinct, trail of smoke. The explosion is usually too distant to see, but is very loud nonetheless. The ship always crashes in the same location.

Alternatively, if the Sole Survivor activates Relay Tower 1DL - 109 a radio signal will be discovered titled "Garbled Radio Beacon." If the Sole Survivor tunes their radio to the frequency they can travel east and the signal will resolve to a higher quality until the Sole Survivor discovers what appears to be a crashed alien vessel

Layout
The site features a half-buried UFO in a hillside with a skid area of destruction including broken trees, flattened ground, and scattered flames. The trees all around will be permanently on fire, making the location easier to spot from afar. There isn't anything particularly valuable about the crash site itself (no way to enter the UFO, nor anything to scavenge at the crash). Next to the still burning UFO is a trail of green blood. The Sole Survivor can follow the trail of green blood, slightly north, down into a ravine, and then into a nearby unmarked cave.

Inside the cave is an alien with an alien blaster pistol and 400-500 alien blaster rounds. If the alien is targeted in VATS, the will show that its right leg is crippled, presumably a result of its apparent crash landing. On sight, the alien will immediately attack the Sole Survivor. Next to the alien is a human skeleton and a Ham radio that might be the source of the nearby Garbled Radio Beacon, although the beacon cannot be disabled using the radio.

As of yet the origin and original intent of the Alien is unknown.

Appearances
The crashed UFO appears only in Fallout 4.