The entrance is on the circus level ( i don't remember for sure what level number that is - i think it is the 4th or 5th level ). On some point of the level there is a lake. Jumbing on the lake and searching the bottom you shall see a entrance, and going through it you will find a secret cave. In this cave there is a strange object with 3 symbols on it. Its a lottery machine. Turning the symbols, 2 things can happen as i remember. Either you die or you are sended to the clown secret level... Believe me, you must see this level
