Just south of the National Museum is the spectacular Sanjusangendo, the Hall of Thirty-Three Bays. 
The Sanjusangendo have an underground tunnel that leads to the National Museum. 
mnli hypothesis: The Sanjusangendo have an underground tunnel that leads to the National Museum.  premise: Just south of the National Museum is the spectacular Sanjusangendo, the Hall of Thirty-Three Bays. 