The Magnolia Petroleum building (now just the Magnolia Building or Magnolia Hotel) was a steel reinforced structure that soared 29 stories over downtown Dallas.  It actually soared over more than Dallas as it was the tallest building in Texas at the time.
Not just tall, but cool.  Rumor has it, the Magnolia was the first high-rise to include air conditioning.  If you have ever been to Dallas, you know you don’t want to be ‘upstairs’ in August without air conditioning.  And all of those oil execs needed to keep their shirts dry.
It has been lovely during the day here in Dallas – no air conditioning required.  You should make use of that and book a tour.