Bangkok - Wat Arun

Bangkok - Wat Arun, a photo by GlobeTrotter 2000 on Flickr.

The famous Wat Arun, perhaps better known as the Temple of the Dawn, is one of the best known landmarks and one of the most published images of Bangkok. It consists of a massive elongated prang (Khmer-style tower), and is surrounded by four smaller prangs.
The Wat really looks better from a distance than close up, and you're not missing out too much even if you only view from across the river. The grounds are fairly pleasant and peaceful though, with good murals and a main Buddha image supposedly designed by King Rama II.
It is possible to walk a limited way up the (very steep) stairs of the main prang, which gives a reasonable view of the Chao Phraya river.

Despite it's name (coming from Aruna, the Indian god of the dawn), the best views and photos of Wat Arun are in the evening with the sun setting behind it. There are some restaurants on the opposite side of the river that are good for watching this, though you'd be lucky to see the image of Wat Arun that's on all the postcards - that of the red sky sunset with the sun setting directly behind the temple. Sunset is around 6pm - 7pm all year round in Bangkok.