The enormous chedi at Wat Yai Chai Mongkol, the largest in Ayutthaya, was constructed by King Naresuan after he defeated the Burmese crown prince during a battle atop elephants in 1593. (A recent painting of the battle is one of the highlights of the temple.) The chedi is now leaning quite a bit, as later enlargements are weighing down the foundation. The complex, dating from 1357, was totally restored in 1982. Linger a while to pay your respects to the huge reclining Buddha, or climb to the top for a spectacular view. The site closes at 5 pm, but you can enter after that if the gates are left open, as they often are. The view at sunset is beautiful, and you'll completely escape the crowds.
Ayutthaya to Bang Pa-In Rd., about 5 km (3 miles) southeast of the Old City, Ayutthaya, 13000, Thailand