Simplify the following text for a Grade 4 native English-speaking person.
Original: It was temporarily opened to the public on 23 May 2009 , during the school 's annual Open House to showcase the Humanities curriculum in the Raffles Programme , as well as the Humanities Club . It was officially in use by Term 3 in 2009 .
Simplified: It was temporarily open to the public on 23 May 2009 .