A holiday season tradition opens this weekend in Pella.  Pella Historical Village Director Patsy Sadler says the grounds are all set to go again for the 31st annual Christmas Walk.  Featured are twenty decorated buildings at the Historical Village and a total of over thirty decorated trees.  Admission is eight dollars for adults and two dollars for students.  The Christmas Walk at the Pella Historical Village is open today through December 31st, except on Sundays and holidays.