Hierachical Fields

Hi

I'm new to Drupal and have been pulling my hair out now for quite a few days now trying to configure something that I would have imagined to be a very basic requirement.

All I need to figure out is how to create some kind of hierarchical field select system for locations in this instance. For example I have UK Counties (taxonomy), I would then like for arguments sake to select West Midlands and then a second field should dynamically show all the towns in the West Midland's area to enable the user to select one.