On a forested hillside at the edge of Phetchaburi, Phra Nakhon Khiri Historical Park (Khao Wang) includes one of King Rama IV's palaces and a series of temples and shrines. Many of these are set high on the hilltop and have good views. Monkeys are a major shoplifting hazard around the gift shops at the foot of the hill. There's a cable car (B50) for those who don't fancy the strenuous walk.
Entrance off Phetkasem Rd., Phetchaburi, 76000, Thailand