The Royal Palace

Cambodia's government is a constitutional monarchy. The king acts as the head of state while the prime minister, the head of government. The king resides in the Royal Palace while the prime minister lives...in his own house, I guess :-)
The Royal Palace, located in the capital, Phnom Penh, is open daily from 730 to 11 in the morning and from 2 to 5 in the afternoon. Admission is US$6.25. Most of the buildings in the palace compound is open to the public.
A map of the palace grounds
When visiting the palace, one must wear the proper attire: sleeved shirts, and pants or knee length shorts. This we did not know and had to rent a pair of Thai fisherman pants for US$0.25 (with a deposit of US$5). And if you're like my friend here, wearing all the wrong things (short shorts and sleeveless shirt), fortunate if you have an extra shirt with you (which she did not have), lucky if your tuktuk driver lends you his long sleeved shirt! (Yes, our tuktuk driver was wearing that shirt and he took it off to lend it to her!)
 The proper attire
You can explore the palace on your own or hire a guide to show you around. I would suggest the latter to appreciate the significance of the buildings and the items found inside. Our guide charged US$10 for our group of five. One of the questions we asked him was: Who is the King of Cambodia? Norodom Sihamoni. A dancer. A bachelor. Age 53. And  because of these three things, our guide concludes the king is really the queen.
Our guide telling us about the cannonball tree
You can find all the riches of Cambodia in this 175,000 square meter space. From gold statues to silver-tiled floor to an emerald Buddha adorned with thousands of diamonds. (Sorry, no photos since it is not allowed.) A tour around the Royal Palace will take at least an hour. Here are a few of the structures in the palace complex:
The Throne Hall is where coronations and meetings with foreign dignitaries and government officials take place. The one and only time the king sits on the throne is when he is crowned.
Chanchhaya Pavilion, also called the Moonlight Pavilion, is where banquets are held.

Napoleon III Pavilion (Photo source)

One structure that I should mention, but failed to take a photo of (it was under restoration at that time), is the Napoleon III Pavilion. It looks different from the other buildings for it is European in style. It was a gift from Napoleon Bonaparte to King Norodom in 1876. Originally built in Egypt, it was dismantled and sent to Cambodia.
 Pagoda of the Emerald Buddha or the Silver Pagoda, so named because of its silver-tiled floor
(5,000+ silver tiles, weighing 6 tons).
 The Library houses sacred Buddhist texts. Fortune tellers work inside the shrine.
 This is the stupa containing the ashes of the current king's grandmother and grandfather.
There are other stupas containing the ashes of former kings.
Phnom Penh in 24 hours:
Thought You Should Know That...
A Bed to Sleep On
The Royal Palace (you're here!)