Ancient Nubia occupied the territory beyond, or upriver, the first cataract while Ancient Egypt occupied the lands below, or downriver, of the first cataract. Historians have come to divide Nubia itself into sub regions with Lower Nubia comprising the lands between the first and second cataract and Upper Nubia being the regions beyond the second cataract.
How You Burn Calories. Your weight x distance = energy used walking. Time does not matter as much as distance. If you speed up to walking a mile in 13 minutes or less, you will be burning more calories per mile. But for most beginning walkers, it is best to increase the distance before working on speed. A simple rule of thumb is 100 calories per mile for a 180 pound person.
Obviously it'll be different for everyone, but my own stats from back in January say that I burned around 34 calories a mile cycling, whereas I burn around 100 calories a mile on foot. However, my bike rides would have me doing 2 miles in 15 minutes, whilst I covered 1 mile in 20 mins when walking. So, I could walk for an hour and burn 300 calories, or I could cycle for an hour and burn 272 calories. Not all that much different, at that level.