WAT RAK (วัดรัก)
Wat Rak or the "Monastery of the Crown Flower" was situated on Ayutthaya's city
island in the
Historical Park in Pratu Chai sub-district. The temple was located on the
east bank of
Khlong Chakrai Yai, called Khlong Tho in its northern stretch.

On its south stood
Wat Chana Man (no traces anymore); opposite Khlong Chakrai were
Wat Kao (no traces anymore) and Wat Khun Phrom. In the east stood Wat Pa Mo (no
traces anymore), the name at par with Khlong Pa Mo, a canal running just south of the
temple, being an extension of
Khlong Klaep/Khlong Tha Phra.

There are no traces of foundations or brick work at ground level and the temple is
classified as disappeared.

The site is mentioned on
Phraya Boran Rachathanin's map drafted in 1926 and on a
mid-19th century map. The position of  the temple matches both maps.

Historical data about the monastery and its construction is unknown.

The monastery was likely named after the Calotropis Gigantea or Crown flower, a
species of Calotropis native to Cambodia, Indonesia, Malaysia, Philippines, Thailand, Sri
Lanka, India and China. It is a large shrub growing to 4 m tall. Its flowers are strung into
garlands to be worn around the necks of criminals on their way to the place of execution.
In Thailand the Rak tree grows wild in deserted dry places. Its trunk and branches have a
milky sap and its flowers are used for floral pieces which are to be seen usually at
cremations. Today it is the fashion for a bride and groom to wear a garland of these
flowers, for the name "rak" means "love" in Thai. [1]

References:

[1] Some Siamese Superstitions about Trees and Plants - Phya Anuman Rajadhon - JSS
Vol 49.1 - 1961 - page 58.
Text & maps by Tricky Vandenberg - October 2009
Reviewed February 2011, January 2013
(Extract of a begin-20th century map)
(Extract of a mid-19th century map)