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, such as 43°00'00" N 72°00'00" W. The project uses the WGS84 datum to define the confluence location.

Initially, the information in our database about confluences was entered both manually and by extracting data from various sources. Since then there have been various updates, both manual and automated, and when someone finds an error and lets us know, we make the correction. Some confluences have been added or changed, where they were in the oceans but a mathematical model shows that they should have a view of land. The altitude listed for a confluence usually comes from a digital elevation model and may not be accurate. The data used to make the distinction between “Water” and “Ice Cap” may not be accurate, and polar ice caps change over time.

We have two sets of confluence information in our database. For all of the 64,442 possible degree confluences, we have some basic information. For the 24,461 degree confluences that we have “indexed”, we have additional information, such as the nearest town, and we have assigned the confluence to a “geographic area”, such as a country. All of the 64,442 possible confluences have been assigned to one of three categories—Land (21,541), Water (38,411), or Ice Cap (4,490). Confluences that are on “Land” are those that our data shows as being located on a continent or an island. Confluences not on “Land” are on “Water”, except for areas with permanent ice, which are categorized as “Ice Cap”, such as confluences near the North Pole.

The goal of the project is to visit each of the latitude and longitude integer degree intersections in the world, and to take pictures at each location. The pictures, along with a narrative describing the adventures it took to get there, are then posted on this web site. This creates an organized sampling of the world.

Another goal is to document the changes at these locations over time. Although we initially want to visit as many different locations as possible, don’t hesitate to revisit a confluence if you’re in the area.

We’ve excluded confluences in the oceans and dropped some near the poles, but there are still 12,185 to be found. You’re invited to help. There is a confluence within 49 miles (79 km) of you if you are on the surface of earth.