Simplify the following text for a Grade 7 native English-speaking person.
Original: Mycenae ( Greek MykÄ `` nai or MykÄ `` nÄ `` ) is an archaeological site in Greece , located about 90 km south-west of Athens , in the north-eastern Peloponnese .
Simplified: Mycenae ( Greek MykÄ `` nai or MykÄ `` nÄ `` ) , is an archaeological site in Greece . It is about 90 km south-west of Athens , in the north-eastern Peloponnese .