Ms Cadogan, nee Scott, has walked everywhere throughout her 100 years to maintain her health.
She celebrated her milestone birthday yesterday with her family at Brooklands Retirement Village in Mosgiel.
Her son, Ray Cadogan, was at the retirement village to celebrate the birthday with her.
Walking was a big part of her life and "might" have been the secret to her reaching the milestone as she was very health conscious, Mr Cadogan said.
"She’s always taught us that you shouldn’t be drinking alcohol and smoking cigarettes because they’re bad for you."
She never indulged in either substance and preferred to spend time reading, sometimes up to four books in a week, he said.
She has lived most of her life in Dunedin and Mosgiel and attended Forbury School and King Edward Technical College.
When she finished school, she worked as a secretary at a law firm and then travelled to Europe, where she lived for five years.
As the second youngest of six children, Ms Cadogan had two brothers and three sisters, all of whom she has outlived.
"She did very well. I’m very surprised that she outlived all her brothers and sisters."
Faith was very important to her, he said. She is a member of the Mosgiel Presbyterian Church.
"That’s a big part of her life."
She moved into the retirement village in June last year, he said.
Ms Cadogan has four children; a son and three daughters.
