Best Optical Illusion Ever

I'm not even kidding. This is the coolest thing ever. The image and text come directly from the "Mighty Optical Illusions" blog.

"To my knowledge, John Sadowski is the original creator of this type of illusions. This is how it works: just stare at the dot for 30 seconds. This is animated gif file, that keeps repeating infinately. After about 20 seconds, grey scaled image of spanish castle will appear, but as your eyes adapt to the inverted image you were seeing first, you will see black&white image change to COLOR! Amazing! For original, full sized illusion, visit John's website. There is also a movie clip available. If you would like to make your own Color Illusion, you should read this tutorial. If you make one, be sure to post link in comments! Previously we posted simmilar illusion. Check it here."