Santa and Mrs. Claus made a surprise visit to Toronto's Hospital for Sick Children on Thursday afternoon.

They arrived as patients were in the midst of writing their Christmas letters set for the North Pole.

Canada Post today launched its annual Santa letter-writing program which has been running for 34 years.

This year, more than 1.5 million letters will be received at Santa's North Pole Post Office, with the most famous postal code of all: HOHOHO.