Confluence.org :

"A confluence is defined as a flowing together; a meeting place (often of rivers). In our case a degree confluence is the exact spot where an integer degree of latitude and an integer degree of longitude meet."

"I (Alex Jarrett) started the project in February 1996 because I liked the idea of visiting a location represented by a round number such as 43°00'00"N 72°00'00"W. What would be there? Would other people have recognized this as a unique spot? Another reason was that my friend managed to convince me to buy a GPS and I had to come up with something to do with it. I also hoped to encourage people to get outside, tromp around in places they normally would never go, and take pictures of it."