La Zona Del Silencio , or the Zone of Silence, is a patch of desert near the Bolson de Mapimi in Mexico, in a place known as the Trino Vertex.
Magical zona del silencio–the Zone of Silence, just four hundred miles away from El Paso, Texas. Deserts are often considered to be mysterious enough without the added weirdness that this patch of earth some four hundred miles from El Paso has to offer. It is a place which gobbles up radio and TV signals, and which has of late been associated with the UFO phenomenon.

Other, more unexplainable, activity of this nature is reported here, such as the area’s reputation for strange lights, UFO sightings and alien encounters. Some even believe it has been used in the past—and present—as a portal for aliens. Ranchers have cited tales of strange lights and odd strangers that appear from nowhere and claim to come “from above”.
In fact, the same three blonde strangers have often been spotted by multiple witnesses. Also, the witnesses of some of the unexplainable flying objects—some being described as ‘disc-like’—that were thought to have landed found physical evidence in the form of burned brush and vegetation at the touchdown sites.

On an interesting note, the Zone of Silence is geographically parallel with the Egyptian pyramids and the Bermuda Triangle , and is located just north of the Tropic of Cancer.
Scientists at the Mexican research center have coined the area the Sea of Thetys because it lay at the bottom of an ocean millions of years ago.

The numerous boulders and earthen mounds of various topographies, some up to 20 meters in height, have been sculpted by the elements into artistic shapes that seem as if they have been crafted by human hands, and that have been variously described as resembling castles, stairs, pavilions, temples, pagodas, walls, palaces, vehicles such as buses and boats, human faces, animals, and strange, terrifying creatures.

The most bizarre aspect of the Demon City are the inexplicable mysterious sounds said to emanate from it and the surrounding area. The sounds come in many variations. It is said that during the day, one can hear what sounds like guitar strings being plucked, the tingling of bells, and human voices whispering, shouting, and even singing.
Even creepier, there are times when these sounds pervading the air take on the quality of moaning, screaming, quarreling, or of babies crying. At night and when the frequent strong winds that lash the region come to send sand and gravel whipping through the air, the mystery sounds transform into a frightening cacophony that is described as reminiscent of lions roaring, wolves howling, elephants trumpeting, and pigs being slaughtered.

The sources of these strange sounds are not clear, and most of the time they are said to seem to come from all directions at once, as if materializing from the air itself. Locals believe they are the voices of ghosts, spirits, or demons. Although it is more likely that the sounds are some as yet misunderstood effect of the wind on the various unusual Yadan landforms, it is still a mystery as to what causes this weird phenomenon, and research into the acoustics of the area has been inconclusive.