Wat Phu Khao Thong is often called "Golden Mount Pagoda" and was built in 1387. The site originally housed a large Mon-style Chedi built by King Hongsawadi of Burma to commemorate his victory in Ayutthaya in 1569. During restoration during the reign of King Boromakot a new Thai-style Chedi was built on the base of the former Chedi. This Chedi can be seen today and is around 80 meters tall. There is a gold ball at the top of the Chedi which ways around 2 kilogrammes as well as a Buddha footprint from Saraburi. The temple is slightly off the beaten track and although not far away from the old city, if you are short of time other sites might have priority.
Details: The site is open daily and admission is 20 Baht for adults.
How to get there: The temple lies in the north Ayutthaya outside of the old capital. It is easily accessible by Tuk-Tuk.