Hot Stuff?

Have you ever wondered what is in the center of the earth? According to Biggest Book of Questions and Answers, it is hot solid rock.  It states that Earth has four layers:  The Crust, The Mantle, The outer core and the the core.  The Crust supposedly down about 20 miles (five miles under the oceans).   The mantle is 1,800 miles deep.  The core is 1400 miles of hot liquid rock.  Lastly, we are to the core, which is 800 miles thick, a ball of hot, hot 12,000 degrees Fahrenheit hot, solid rock.  There is a hell afterall.