Visiting Bangkok and not visiting Wat Phra Kaew is a no go. Be prepared to spend some time exploring all the sights. I especially loved the wall paintings, located in the outer wall of the temple. But also the different and very colourful buildings are must see. Be sure to bring your camera and an extra battery (they unwind quite fast in the heat and when taking lots of pictures). In the hall of the Emerald Buddha one is not allowed the take photos. It's a huge building with lots of gold and a rather small Emerald Buddha! Too me a big fuss for not so much. Still worth seeing.