Ayutthaya, formally known as Phra Nakhon Si Ayutthaya, was the capital of the Kingdom of Siam for 417 years and is today one of Thailand's most significant archaeological destinations. Founded in 1350 by King Ramathibodi I, the city once rivalled the great European capitals in size and grandeur — by the early 1700s it had a population exceeding one million, making it one of the largest cities on earth at a time when London counted fewer than 100,000 residents. Situated at the confluence of three rivers — the Chao Phraya, the Pa Sak, and the Lopburi — the city was effectively an island, connected by a network of canals that earned it the nickname 'Venice of the East.'
The Ayutthaya Historical Park, designated a UNESCO World Heritage Site in 1991, preserves the ruins of the old city across an area of roughly 289 hectares. Its most photographed sight is the Buddha head entwined in the roots of a banyan tree at Wat Mahathat, a haunting image that resulted from centuries of natural growth engulfing a stone head left among the rubble after the Burmese sacked the city in 1767. That destruction was so comprehensive — temples burned, statues decapitated, libraries torched — that the Siamese court abandoned Ayutthaya entirely and established a new capital downriver at what became Bangkok.
Beyond Wat Mahathat, key temple ruins include Wat Phra Si Sanphet, whose three iconic chedis once held the ashes of Ayutthayan kings; Wat Chai Watthanaram, built in Khmer style to commemorate King Prasat Thong's victory over Cambodia; and Wat Lokayasutharam, home to a striking 42-metre reclining Buddha. The city's cosmopolitan history is visible in the Japanese Village (Mu Ban Yipun), where 17th-century samurai traders and mercenaries settled and served as royal bodyguards, and the Portuguese Settlement, one of the earliest European trading posts in Southeast Asia, established around 1511.
Bang Pa-In Royal Palace, located a short drive south of the old city, showcases a remarkable blend of Thai, Chinese, Gothic, and Victorian architecture built as a summer retreat for the Thai monarchy. Ayutthaya is easily reached from Bangkok — roughly 80 kilometres north — by train, minivan, or boat, making it one of Thailand's most popular day-trip destinations. However, staying overnight allows visitors to experience the temples illuminated after dark and to cycle the quiet island roads at dawn before the tour buses arrive.