After breakfast, explore some of the numerous magnificent structures and ruins concentrated in and around the city island of Ayuthaya, surrounded by the Chao Phraya, the Pasak, and the Lopburi Rivers. Visit the important historical sites of Wat Si Sanphet and Wat Yai Chai Mongkol located in the historical park which has been included in UNESCO’s World Heritage list. Then continue your trip to Khao Yai National Park, which covers an area of 2,168 square kilometers in the Phanom Dong Rak mountain range, stretches over 4 provinces including Nakhon Ratchasima, Nakhon Nayok, Saraburi, and Prachin Buri. Khao Yai became Thailand’s first national park on 18th September 1962 and is also originally recognized as the National Park Heritage of Asian Group Countries. The park is comprised of mixed forests and rainforests with some wide plains and grasslands interspersed with verdant forests. There are many valuable plants, including commercial plants, scented plants, and herbs. In addition, there are several mountains with peaks ranging from 800 to 3,000 meters above sea level making Khao Yai a cool climate area, even in summer. Guests enjoy a mini trekking tour between 3 and 8 km through the dense tropical rainforest of Khao Yai. Appropriate shoes and binoculars are recommended. Overnight at the hotel in Prachinburi.