Wat Phra Kaew itself is the main attraction though. This is Thailand's most important and sacred temple, so you're expected to act with due respect inside it. It houses the tiny (between 60 and 75 cm) Emerald Buddha, which is located high above the heads of the worshippers and tourists. Not much is known for certain about the statue, except that it isn't actually made of emerald but rather of green jade or jasper. Getting a good look at it is difficult as photography is forbidden inside the temple, and it's perched so high up inside it's glass box that it's difficult to see in detail.
It's thought to have been made in the 15th century and was the cause of several wars before ending up for good in Bangkok in 1782. The image is considered a talisman and holds tremendous significance for Thailand and the Thais. The 'robe' that it wears is changed 3 times each year by the King himself, at the start of each season: A diamond encrusted gold robe during the hot season, a solid gold robe in the cool season and a gilded monk's robe in the rainy season.There are also many other Buddha images inside the temple.