It is a dirty city though. You have to take the good with the bad. As Doc said, the monuments and various memorials will take up a vast majority of your time.
Being the capital city, there are places to get every kind of food that you could ever possibly imagine eating. There are also tons of photo ops if you're into the whole picture taking thing.
I have not been there for what is going on 4 years, but I REALLY want to go back in the near future now that I am old enough to actually appreciate it.