Architect Louis Kahn has been gone almost 50 years, but his legacy and influence only grows as architects the public alike cherish his enduring importance. His major works include the National Parliament in Dhaka, Bangladesh; the Salk Institute in La Jolla, California; the Kimbell Art Museum in Fort Worth Texas; and the Four Freedoms Park on Roosevelt Island in New York City. Kahn was also a revered educator, teaching at Yale and The University of Pennsylvania. Joining us today Michael Merrill, author of the new book Louis Kahn, the Importance of a Drawing, and filmmaker Nathaniel Kahn.  Yes, he's related.