Simplify the following text for a Grade 3 native English-speaking person.
Original: There are so many forests and parks in KÃ penick is sometimes called the `` green lungs '' of Berlin . The MÃ 1\/4 ggelberge hills in the south-east of KÃ penick reach , making them the highest natural point of Berlin .
Simplified: During the Cold War , KÃ penick was part of East Berlin .