UFO in Spain
UFO-like cloud spotted in SpainYouTube: Cisimo

Even though space agencies like NASA and ESA are searching for alien presence in the deep nooks of the universe, conspiracy theorists strongly believe that extraterrestrials are already here on the earth.

In order to substantiate these seemingly unbelievable theories, they often put forward the examples of mysterious UFO sightings that had happened in various parts of the world. One such UFO incident apparently happened in Spain, and it has made many people believe that alien existence is a real deal. 

Presence of intelligent aliens on earth?
In the mysterious video, a strange cloud, in the shape of a classic flying saucer can be seen hovering in the skies of Spain. At the first glance, the UFO literally reminded the alien motherships often depicted in Hollywood movies like Independence Day and Mars Attack. 
The video was later analyzed by popular conspiracy theorist Scott C Waring. After analyzing the video, Waring argued that the alien UFO is making use of the cloud to hide its presence so that people will not get panicked. 
"What we see here is a huge UFO that has created a cloud around it in order to not frighten the public. It probably is moving from a base under the ocean floor to a new location. The object also seems to be moving very fast, too fast to be a cloud. The disk itself is perfectly balanced and mimics the alien disk shape perfectly. This is an alien ship," wrote Waring on his website UFO Sightings Daily
Lenticular Clouds: A convincing explanation
Even though Waring and his followers consider the mysterious object in Spain as a UFO, skeptics have already made it clear that these are actually lenticular clouds. According to these skeptics, lenticular sightings quite common, and most of these cloud structures are formed in the shape of a dome or flying saucer. 
NASA, on their website, reveals that lenticular clouds are formed when moist air is forced upward near a mountain or volcano.