After 13 years with the Royal Mail, you might think Peter Willis could happily spend his retirement（退休）without ever seeing another post box.
But the postman has decided to keep himself busy by photographing as many of Britain's 115, 000 post boxes as possible.
The 67-year-old man has covered thousands of miles taking pictures of 2,500 post boxes since he started this great activity five years ago.
Mr Willis, who worked as a Royal Mail manager before he retired, said, "It started out as a bit of a hobby but has developed into a bit of an obsession（痴迷）. There is something wonderful about discovering a post box which is in a strange location or is particularly old but is still being used by people to communicate with each other. When I've taken a picture of a post box, I will remove it from the list. I'm not sure whether I can get round all 115,000. I've done around 2,500 boxes and I'm always looking out for the next one. "
He takes his wife Dianne, 64, with him along the way. "She often stands guard if I'm in the middle of the road taking pictures as I get down on my hands and knees to record the bases, which have details of the producers on them. She is usually telling the passing public that I'm not actually mad. I suppose she gets a bit bored sometimes. Sometimes she'll let me go off on my own." said Mr Willis.
Over the past years, Mr Willis has photographed post boxes in Inverness, Dublin and across England. His photos include unusual locations, such as several post boxes at the top of hills and even one inside a theatre.
When he finds a new post box, Mr Willis photographs the base to record the producer's name and gives a grid reference（坐标参考）on a map.
