This is a shot of the engine bell of a <a href="https://en.wikipedia.org/wiki/en:Space_Shuttle_Main_Engine" class="extiw" title="w:en:Space Shuttle Main Engine">space shuttle main engine</a> (SSME), like the ones found on the space shuttle in this photo, but extracted from a shuttle itself.  This helps show how large the engine bells are.  The tubing around the engine bell helps cool it when it's in use, and there's over two miles of this tubing (usually copper pipe)!
<p>To see a large view of the space shuttle's tail, see <a rel="nofollow" class="external text" href="https://www.flickr.com/photos/fastlizard4/8657654408">here</a>.
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This photo of the Space Shuttle <a href="https://en.wikipedia.org/wiki/en:Space_Shuttle_Endeavour" class="extiw" title="w:en:Space Shuttle Endeavour"><i>Endeavour</i></a> exhibit was taken at the <a rel="nofollow" class="external text" href="http://www.californiasciencecenter.org/">California Science Center</a>, the "retirement home" (if you will) of this particular shuttle.  If you live in the area, go check it out; entrance is only $2!
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/25649741@N04">Andrew "FastLizard4" Adams</a> from United States
CC BY-SA 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/fastlizard4/8657671558/">Space Shuttle Main Engine Bell</a>