After a long flight from JFK, you will arrive at Suvarnabhumi Airport, Bangkok's main airport. You can take a taxi or the airport rail link to get to your hotel. Spend the rest of the day exploring the surrounding area and trying some local street food.
Visit Wat Phra Kaew, the Temple of the Emerald Buddha, and the adjacent Grand Palace. The temple is one of the most revered in Thailand and contains a small, but beautiful Emerald Buddha statue. The Grand Palace is a complex of buildings that served as the residence of the Thai monarch for over 150 years.
Explore the Chatuchak Weekend Market, one of the largest markets in the world. With over 15,000 stalls selling everything from clothing to antiques, you can spend hours browsing the various sections. If you get hungry, there are plenty of food stalls selling local cuisine.
Travel to Ayutthaya, the second capital of Siam, and visit the Ayutthaya Historical Park. This UNESCO World Heritage Site consists of the ruins of numerous temples and palaces that date back to the 14th century. Don't miss the iconic Buddha head statue entwined in tree roots at Wat Mahathat.
Take a day trip to Erawan National Park and hike the trail to the seven-tiered Erawan Waterfall. The hike can take anywhere from 1-3 hours depending on your fitness level. The turquoise waters of the waterfall make for a great swimming spot.
Visit Wat Arun, the Temple of Dawn, and take a boat tour of the Chao Phraya River. Wat Arun is located on the west bank of the river and has a distinctive Khmer-style tower. The boat tour will take you past some of Bangkok's famous landmarks, such as the Temple of the Reclining Buddha and the Royal Barges Museum.