The temple is known as Wat Pha Khao Thong is located in Ayuthaya. It has a chedi, known as Chedi Phu Khao Thong (เจดีย์ภูเขาทอง) is located near The Monument of King Naresuan located in Ayutthaya.
After climbing up the stairs of the chedi, you can opt to go inside the middle area. This is what you see inside. Note that the picture below was taken under night vision using flash. The insides is quite dark actually.
Below: A close up of the Buddha statue.
From the top, the scenic view is also very beautiful.
Phu Khao Thong,
Phra Nakhon Si Ayutthaya District,
Phra Nakhon Si Ayutthaya