This mosque is one of the oldest mosques of Boushehr and had been closed to the city wall in past. Ghavam water reservoir also is located beside of this mosque.Why fil?
Fil in Persian language means elephant. According to an old local history, the building of the mosque was unfinished. After aggression of British army to Iran and invasion of this county, Indian workers from Indian Eastern Company came to Iran along British officers. Fostering the elephants for circus was one of their businesses in Iran. The coach of a famous circus in Boushehr was Muslim and that’s why he came to the mosque every day to pray within his small elephant. He decided to complete the building of the mosque by coordination of the grandees of Boushehr. After end of constructing of the mosque, he nominated the mosque as Fil. Nobody knows exactly that what had been his purpose of Fil. It  could means his small elephant or the Fil Surah of Quran.