C# Call Graph Generation Tool

Question

I just got a heaping pile of (mostly undocumented) C# code and I'd like to visualize it's structure before I dive in and start refactoring. I've done this in the past (in other languages) with tools that generate call graphs.

Can you recommend a good tool for facilitating the discovery of structure in C#?

UPDATE

In addition to the tools mentioned here I've seen (through the tubes) people say that .NET Reflector and CLR Profiler have this functionality. Any experience with these?

Answer 1

NDepend is pretty good at this. Additionally Visual Studio 2008 Team System has a bunch of features that allow you to keep track of cyclomatic complexity but its much more basic than NDepend. (Run code analysis)

Answer 2

Concerning NDepend, it can produce some usable call graph like for example (image full size here)

Find more explanations about NDepend call graph here.