Wat Song was located in the northeastern corner of the city island and more or less just opposite Wat Mae Nang Plum. The northeastern corner of the present Ayutthaya city island was in the beginning of the 16th century dry land, situated outside the city wall fortifications.
The monastery is first mentioned in the Royal Chronicles of Ayutthaya in where is written that in early 1549, a herd of elephants entered a kraal at Song Monastery. 
It indicates that - at that time - the Lopburi River still would have been in its old track (present Khlong Hua Ro) and the Pa Sak River still running east of the city in the present Khlong Hantra bedding. As Steve Van Beek writes: "The Pa Sak River flowed along the eastern perimeter of the city, a few kilometers east of its present course, and joined the main river south of Ayutthaya".  We can derive from this that - prior to the first fall of Ayutthaya in 1569 - elephants could have been chased down on the dry land between the two rivers, right up into the kraal.
Wat Song was prior 1569 located outside Ayutthaya's city walls. After the first fall of Ayutthaya, King Maha Thammaracha (r. 1569-1590), realized the poor defenses of the city and noticed the use of the dry land in front of the city walls by the Burmese attackers. Maha Thammaracha started to upgrade the defenses of the city. He assessed that the eastern part of the city needed a better defense. Hence he ordered in the period 1577 - 1580, the building of a series defensive structures, as the Chan Palace, city wall extensions, fortresses and canal widening. Wat Song as thus, became situated within the city walls and behind the Maha Chai fortress.
Hengpujaroen wrote that according to some old documents, the walls around the Chan Kasem Palace or Front Palace had a length of 50 Sen or approximately 2000 m. The palace occupied thus an area roughly going from the Unmilled Rice Fort (Pom Khao Phluak) and Wat Tha Sai towards the Maha Chai Fort; going down to the Ho Rattanachai Gate and running back along the Ho Rattanachai canal towards the Unmilled Rice Gate. The palace area should have included at least eight monasteries, which one of them was Wat Song. The issue of such a large palace ground as mentioned here, was although heavily discussed by scholars and rejected.
At present nothing remains of the former monastery, which location should have been where the present Hua Ro market is situated.
 The Royal Chronicles of Ayutthaya – Richard D. Cushman (2006) - page 24 / Source: Phan Canthanumat, British Museum, Reverend Phonnarat, Phra Cakkraphatdiphong & Royal Autograph.  The Chao Phya River in Transition - Steve Van Beek (1995).  The study of Chantharakasem Palace for developing the Management Plan - Nantana Hengpujaroen (2003).  อธิบายแผนที่พระนครศรีอยุธยากับคำวินิจฉัยของพระยาโบราฌราชาธานินท์ ฉบับชำระครั้งที่๒และภูมิสถนกรุงศรีอยุธยา (2007) - Explanation of the map of the Capital of Ayutthaya with a ruling of Phraya Boran Rachathanin - Revised 2nd edition and Geography of the Ayutthaya Kingdom - Ton Chabab print office - Nonthaburi (2007) - page 92.
Text & map by Tricky Vandenberg - August 2009 Reviewed May 2011