Haroon Mosque, established in 1837 by Indonesian-Arab trader Musa Bafadel, is one of Bangkok's oldest and most significant Islamic sites. Originally a wooden structure known as "Masjid Ton Samrong," it showcased a blend of Javanese and Ayutthaya architectural styles. In 1899, under King Rama V, the Thai government relocated the mosque to make way for the Royal Custom House, offering Bafadel's son, Muhammad Yusuf, an inland site in exchange. By 1934, the original wooden mosque was replaced with a brick and lime structure, renowned for its size and intricate craftsmanship. Registered as Mosque #2 under the Royal Act of Islamic Mosques in 1947, Haroon Mosque remains a central hub for Bangkok's Muslim community, hosting daily prayers and religious events.