Working in ArcGIS 10.4. I have a rivers dataset, and I want to create a point wherever two rivers meet (tributaries join with other rivers, etc.). I tried the Intersect tool, but I think that tool requires more than one input dataset. I have Network Analyst, if that helps.
"Could creating a geometric network solve the problem? (ArcCatalog > Geodatabase > Feature dataset > Geometric network). Junctions will be created automatically at the intersections of the rivers."
Spatial ecology plugin does it simply as well. The tool is isectfeatures (Intersect Features)
If you specify a single input feature data source, then it calculates intersections between geometries within that dataset.
Or just do as Richard states.
The Intersect tool does not require two inputs. The help for How Intersect (Analysis) works says "Intersect can run with a single input. In this case, instead of discovering intersections between the features from the different feature classes or layers, it will discover the intersections between features within the single input. This can be useful to discover polygon overlap and line intersections (as points or lines)."
You have to be sure to change the output type to Points to get the intersection points created, since otherwise the tool will try to find only overlapping line segments.
The other thing you might try after you've created a correct network is the feature vertices to points tool, with either start, end or both ends option (just in case your stream network is not correctly digitized). This tool is located in the Data Management -> Features toolbox.