A Chedi is a a bell-shaped tower. Another word for chedi would be a pagoda or a stupa. It either contains a relic of the historical Buddha Ghautama or of a Thai king or an important Thai monk. Sometimes also important religious buddhist teachers are buried under a chedi (their ashes is stored under the chedi).
This one is a really nice video clip from the temple of dawn (Wat Arun)
Watch this video with a Thai tourguide in one of Bangkoks temples. If you can actually understand what said, congratulations 
See this free video tour in the Wat Phra Keo temple in Thailand. Wat Phra Keo is where the Emerald Buddha is located and is the most revered buddhist shrine in Thailand. If you ever come to Thailand, there’s a 200 THB admission fee, around 5 USD and it’s well worth to explore such a huge temple complex.
The Wat Arun in Bangkok (also known as Temple of Dawn or Wat Chaeng) can be seen when you stand at the Chao Phraya river nearly the Wat Pho temple. It’s on the other side of the river (Wat Pho is on the East side of the river, Wat Arun is on the West side of the Chao Phraya River).
It has a very unique style compared to other temples in Bangkok. In general, Thai temples are very colorful, but this one is different. It’s decorated with seashells, pieces of Chinese porcelain and colored glass.
The temple was built before Bangkok became the capital of Thailand – back then it used to be Ayutthaya, which is located about one hour north of Bangkok.
According to the TAT (Tourism Authority of Thailand) the temples “prang” is 104 meters high.
Wat Pho is probably the most famous and most visited temple in Thailand – every day it’s crowded with tourists eagerly taking pictures in front of little statues of thai eremits performing thai-yoga exercises.
The Wat Pho is also the temple that has the famous reclining buddha. The statue of the reclining buddha is huge – all gold-plated it’s 64 meters long and 15 meters high. It represents the moment when the buddha died and passed into nirvana. It’s quiet impressive to see that and Thai people have a small ritual that they perform around it. They carry a handful of coins and drop them into 108 prayer bowls. You can get a bowl for yourself (just leave a small donation in exchange).
The Wat Po temple complex is gigantic too – it spreads around 20 acres of land and there is a whole area attached (separated by the temple walls and a small road) where the monks reside.
The architecture is pretty fancy and not exactly what you imagine when you think of an Asian Buddhist temple – it’s Thai style!
The Jakarta Post just had a nice travel writing piece on a Bangkok trip by Prodita Sabarini. Included is a small part on the Grand Palace (with the emerald buddha) and the Wat Pho monastery (with the reclining buddha).
Bangkok has around 400 temples. A Thai temple is open to everybody – so you are free to enter any temple, as long as you have common courtesy and follow a certain dress-style (no mini-skirts, etc. – you don’t want to make the monks horny!).
Some temples charge you to enter them, but these are the main tourist destination temples where there really are high maintenance costs because of the massive influx of tourists – the Grand Palace with the Emerald Buddha and the Wat Poh temple. Most of the temples are done in the modern Thai-style and they are pretty fancy, not like the zen-style Japanese temples. Thai temples are full of colors, mirrors, golden buddhas, colored glass.