Custom taxonomy archive

I have read dozens of threads, but can't seem to find an exact answer.

I have created a custom post type called "recorded_webinars" and a custom taxonomy called "webinar_category". The archive for the custom post type is working fine (http://mysite.com/recorded_webinars/). I need an archive for the taxonomy that looks like:

http://mysite.com/recorded_webinars/webinar_category/

What am I missing?