Simplify the following text for a Grade 8 native English-speaking person.
Original: Architectural and design experts began planning and visiting the site between April and May 2003 , and the area was transformed from swampland to international racetrack within 18 months with a team of 3000 engineers working around the clock .
Simplified: Architectural and design experts began visiting the site by April 2003 . The site was transformed from swampland to an international racetrack in 18 months .