Simplify the following text for a Grade 8 native English-speaking person.
Original: Seoul Festival is an seasonal cultural festival held four times a year every spring , summer , autumn , and winter in Seoul , South Korea since 2003 .
Simplified: Seoul Festival is a seasonal festival sponsored by Seoul Metropolitan Government and others . It has been held for each season â `` spring , summer , fall , and winter - every year in Seoul , South Korea since 2003 .