You are probably thinking of Sweden. I have heard it is actually more now, like 200 years (the article says 140 years). Maybe even excluding the mortgage of the co-op. People are essentially renting from the banks, without any means to default. Apparently they have capped it at 105 years now for new mortgages. (People were actually a bit upset).

https://www.telegraph.co.uk/personal-banking/mortgages/swede...