Simplify the following text for a Grade 9 native English-speaking person.
Original: In 2001 , the preservation society celebrated its 50th anniversary , and in 2005 a major rebuilding and extension of Tywyn Wharf station took place , including a much-expanded facility for the Narrow Gauge Railway Museum .
Simplified: In 2001 , the preservation society celebrated its 50th anniversary . In 2005 a major rebuilding and extension of Tywyn Wharf station took place .