Ninety-seven-year-old Mary has been writing to her best friend Cathy every single day for 77 years.

But Mary and Cathy had a vow, to burn all the letters once they'd read them.

The pair exchanged more than 50,000 letters between them, but none was saved.

Mary has been living in a Barchester care home for the past 10 years.

Reporter: Rachel Coburn; Video Journalist: Mai Noman