Tri-Mountain National Scenic Area Headquarters

Established on May 1, 1899, the Nanzhuang Centennial Post Office was one of the village's three cultural assets during the Japanese colonial period, along with the Nanzhuang Official Residence and Saka. It exhibits many of the village's cultural characteristics and history.

Legend has it that in the past, Saisisyat lived very close to Taay (the little people). Taay taught Saisisyat farming, medicine, and sacrificial singing and dancing, and Saisisyat regarded them as benefactors. Whenever Saisisyat held festivals and ceremonies, they invited Taay to come and drink and have fun.  
   
However, Taay often teased the women of Saisisyat. After enduring this for a long time, Saisisyat decided to retaliate and killed many Taay. The surviving Taay cursed that Saisisyat would suffer from disasters and crop failures year after year, which was true. Saisisyat people, therefore, hold an annual "Pasta'ay" to pray that Taay will no longer harm Saisyat.