Simplify the following text for a Grade 4 native English-speaking person.
Original: Another early building is Fort SÃ # o SebastiÃ # o , built in 1575 and now the SÃ # o TomÃ National Museum .
Simplified: Another early building is Fort SÃ # o SebastiÃ # o. It was built in 1575 and is now the SÃ # o TomÃ National Museum .