Where were Lower Egypt and Upper Egypt located?

In ancient times, Egypt was divided into three kingdoms - Upeer Egypt, Lower Egypt, and Nubia. Lower Egypt is actually the northern part, Upper Egypt is the middle part, and Nubia is the southern part. I know, it's confusing... :)

see http://www.answers.com/library/Wikipedia-cid-3571878Upper and Lower Egypt

for a map of the two Egyptian regions/kingdoms.