I have taken time making this public as nobody wanted to belive me but i know what i saw. we had taken off on our flight home from orlando florida and about 20 mins into the flight i was gazing out the plane window on the right side of the plane. it was pleasent weather outside with good sized clumps of fluffy clouds floating in the sky and we were flying just above them. i was watching them as we travelled by them when i noticed one we were approaching looked very different from the others. there seemed to be something huge projecting out the front half of the cloud and then blending back into it. i could not believe what i was seeing as the plane got closer. the form came into view and there were what looked like huge ancient castle walls blending into the cloud. they had buttresses towards the base and towers. as the plane was passing the cloud i could see very clearly a long very high castle wall with buttresses and castelations along its top, a square castle tower and then the next part of the wall was stepped back a bit. behind the walls, inside, were more walls higher up and could see half of a tower blending back into the cloud. the castle behind all this blended into the cloud. as we flew past the cloud i could see as clearly as if i was flying past a normal castle on the gound, all the sharp edges and details crystal clear of the part of the castle that stuck out the cloud. the castle was a sandy grey in colour. as the plane flew away from the cloud the castle slowley went out of view and i could eventually only see the back of the cloud. i have told only a few people and they have all laughed at me but i know what i saw, it was there as crystal clear as day and it was not just a strange cloud formation, it was a castle within the cloud. i do not have any photo's as was mezmorized by it and it was out of sight within about one minuite, but i could draw it as i can still see it in my head.