The holy missle silo that is the dome of St. Stephen's Basilica. You can climb up to a galley just below the dome, named for its fantastic acoustic properties. From there, it's just another hundred stairs or to the top. Along the way, you're in between the interior and inner dome, getting a detailed lesson in engineering and vertigo.  
 
 
Image Copyright © 2006 Jeremiah Blatz  

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