This is also a nice activity to do.
Even if some people argue that it is becoming too touristic; this is a place where I want to see the sunset.
You can have a wonderful view on the town and you can visit other things with your entrance ticket such as a cave or some temples.
It costs 20000kips to go up which is around 2 euros.
You can have a view on the Mekong, the night market and the Royal Palace.
I let you judge with a picture: