http://www.mathplayground.com/
http://www.coolmath-games.com/
http://mathworld.wolfram.com/MagicSquare.html
In this website we can explore the universe through Hubble’s eye and see the most spectacular images of the cosmos.
http://hubblesite.org/
A fractal is "a rough or fragmented geometric shape that can be split into parts, each of which is (at least approximately) a reduced-size copy of the whole, a property called self-similarity. A collection of fractals in this nice site.
http://www.enchgallery.com/fractals/fracthumbs.htm