Ayutthaya/Wat Ratchbaruna Temple was built by King Borom Rachchathirat the second during the years 1424 to 1448, this was because both his brothers, Chao Yi and Chao Ai died during single handed combat on elephant back.
Initially it was just 2 Pagodas but then he established a Wihan and turned it into a monastery.
The Grand Hall is 63 by 20 meters so this place is pretty big, they charge a 30baht entrance fee to whiteys.
This is close to the Pa Tan Bridge and opposite Wat Mahathat Temple.
This page is not for you if your on a dial up as there are loads of piccies and it will take a long time to load.
I got to admit I did think about going down those stairs but damn they are steep
From TAT
King Borom Rachathirat II (Chao Sam Phraya) built a temple on the site where his two elder brothers were cremated. His two brothers died in a power struggle to succeed their father, King Nakhon In who died in 1424. A series of bell-shaped chedis surround the main prang and a large oblong-shaped viharn is situated at the front.