What are 2 Facts on how the Nile provided protection from Egypt's enemies

The Egyptians were protected from invaders due to their geographical features. For example, they had the Mediterranean Sea to the north along with the Nile Delta. This body of water blocks off land on the other side. ... Furthermore, the cataracts in the Nile to the south protected the Egyptians from lands below them.Egypt relies on the Nile for 90% of its water. It has historically asserted that having a stable flow of the Nile waters is a matter of survival in a country where water is scarce. A 1929 treaty (and a subsequent one in 1959) gave Egypt and Sudan rights to nearly all of the Nile waters.