Wat Rong Khun in Chiang Mai, Thailand is unlike any Buddhist temples in the world.
Prambanan is a Hindu temple in Central Java, Indonesia. The temple was built in 850 CE, and is composed of 8 main shrines and 250 surrounding smaller ones
No one knows exactly when the Shwedagon Paya [wiki] (or Pagoda) in Myanmar was built - legend has it that it is 2,500 years old though archaeologists estimate that it was built between the 6th and 10th century.
Temple of Heaven is a Taoist temple in Beijing, the capital of China. The temple was constructed in 14th century by Emperor Yongle of the Ming Dynasty
Chion-in Temple [wiki] was built in 1234 CE to honor the founder of Jodo (Pure Land) Buddhism, a priest named Honen, who fasted to death in the very spot.
In the 19th century, Dutch occupiers of Indonesia found a massive ancient ruin deep in the jungles of Java. What they discovered was the complex of Borobudur, a gigantic structure built with nearly 2 million cubic feet (55,000 m³) of stones. The temple has nearly 2,700 relief panels and 504 Buddha statues.
The Harmandir Sahib (meaning The Abode of God) or simply the Golden Temple [wiki] in Punjab, India is the most sacred shrine of Sikhism.
Last but definitely not least is the largest temple in history and the inspiration to countless novels and action movies of Hollywood: Ankor Wat.