How did Helm's Deep actually look?

[Peter_20]

I have a really hard time picturing Helm's Deep in my head, and whenever I reach that chapter I go "oh no, Helm's Deep :(".
This chapter is so freaking confusing, I just see this bridge surrounded by hills, and then Tolkien starts talking about some river and a forest and stuff.

How do you picture Helm's Deep?
Could you please describe how it's supposed to look?

[Olmer]

http://img232.imageshack.us/img232/8526/helmsdeepmtolkienzg7.jpg
Tolkien's vision.
http://img232.imageshack.us/img232/8509/helmsdeephildebrandtyo3.jpg
This is how Hildebrandt sees it.

[Peter_20]

Thanks.
However, where does the battle take place in Tolkien's drawing?
And where's that forest that pops up later?