Simplify the following text for a Grade 7 native English-speaking person.
Original: His journeys spanned nearly thirty years and covered almost the entire known Islamic world and beyond , extending from North Africa , West Africa , Southern Europe and Eastern Europe in the West , to the Middle East , Indian subcontinent , Central Asia , Southeast Asia and China in the East , a distance far surpassing that of his predecessors and his near-contemporary Marco Polo .
Simplified: He traveled for nearly thirty years and covered most of the Islamic world . He also explored West Africa , Southern and Eastern Europe , South Asia , Central Asia , Southeast Asia and China .