In Phnom Pen, the motorcycle is King... and often modified to resemble amorphous food stands, or rather sophisticated vehicles to transport people:
Pirogues are also a pretty popular way to get around. Sometimes, you can find entire families living in these slim wooden floats, outrigged with motors.
The National Museum of Cambodia in the Capital holds inestimable collections of Buddahs, old scrolls and decorated stone carvings... Unfortunately, the inside is not ideally maintained (most likely due to lack of funds) but the structure and gardens are beautiful.