After your river adventure, disembark and travel by private minivan to Ayutthaya, via Suphanburi (approximately 4 hours). You’ll have access to a day room, so you can freshen up before your overnight train later tonight. Ayutthaya was the second capital of Siam after Sukhothai, and it became one of the most powerful in Asia with over a million residents by the 18th century. Trading brought great riches to the city, and merchant tales tell of golden palaces, elaborate ceremonies, and breathtaking temples. You’ll see the remains and reminders of its golden age with a guided tour of the historic ruins and temples spread across the town. The rows of headless Buddhas at Wat Phra Mahathat, sacked by the Burmese in the 18th century, are very atmospheric, and a Buddha head surrounded by Banyan tree roots is perhaps the most photographed site in all of Ayutthaya. This evening, head north to Chiang Mai on an overnight train journey, accommodated in air-conditioned sleeping berths (approximately 13 hours).