Orientation
All of Phnom Penh's streets are numbered, some major thoroughfares also have names. The scheme is simple: odd-numbered streets run north-south, the numbers increasing as you head west from the river, and even numbers run west-east, increasing as you head south with some exceptions, e.g. the west side of what was Boeung Kak lake.House numbers, however, are quite haphazard. Don't expect houses to be numbered sequentially in a street; you might even find two completely unrelated houses with the same number in the same street.
