Thornfield Manor is where Jane serves as a governess for Mr. Rochester and it's the very gothic setting for where they fall in love and where Jane hears strange noises. It's the perfect setting to find out that Mr. Rochester cannot marry Jane because he's already married to a madwoman he keeps locked in the attic.
A good picture to represent Thornfield Manor would be of
Haddon Hall, which was used in the 2006 Masterpiece Theater film version of Jane Eyre. It's a real fortified medieval manor house in Derbyshire, England, dating from the 12th Century. A picture of it can be found here: http://hookedonhouses.net/wp-content/uploads/2009/01/haddonhallderbyshire1.jpg