The 27/08/17 at night, around 22:00 my wife call me to look outside saying that she was seeing a strange light over the hills near our house. i was on bed watching tv, we were almost ready to go to sleep. i stood at the side door and we both watch an object that had a cylinder shape with big lightened windows with a random of colors from the white through the orange-red. on top of that hill there´s nothing, close to there there is a site that works like a quarry where they extract construction material. also there is a little village at hills´s skirts. we first thought somebody was up there doing some work, but it was not. the most amazing thing this shape did, was that it made very big explosions of energy lighting a top portion of the hill where it was posed. it was like if it were a giant welding machine finished with an arch of light at the end. the event was already started when we first noticed, it lasted hours; the cylinder ended it´s performance with just a red rounded light blinking from time to time. we stayed watching the event for about 4 straight hrs. finally we got tired and went to sleep. very early in the morning about 7:00 hrs, i peep out at the hill and of course there was absolutely nothing there.