Welcome to Phnom Penh, Cambodia
Phnom Penh is the capital of Cambodia. It's big, dirty, and strikingly underdeveloped in comparison to Thailand's capital, Bangkok. Most people, including me, end up making a trip here with the purpose of visiting the Killing Fields and Museum of the Khmer Rouge, a tragedy that many people do not learn about in school.
The Central Market
I suggest spending a day at the the Central Market (Phsar Thmei). It is a huge yellow building located at Kampuchea Krom and Street 63 selling anything you can imagine. The enormous center is filled with jewelry and the wings contain, clothes, books, art, souvenirs, electronics, food, etc. Go practice your haggling skills - the good thing about the size of this market is if you don't like a price, you can walk away and easily find the same thing the next booth over.
I had to go to the Heart of Darkness club because I loved that book by Joseph Conrad in high school. When I was there, if you could get three girls together you got a free bottle of vodka. This is fantastic or terrible news depending on the person.