The location is a total secret, similar to that of the Mongols, the Huns atleast in this case executed the funeral party so they could never tell anybody the location of Attilas body.

The myth is that his men buried him right next to a river bed, and re directed the river, by digging, over his grave.  It's said his coffin is actually 3 in one, made of iron, silver and gold.  I think that's how it is, I may be wrong about a couple things, but if so, nothing major.  I forgot the name of the river, I'll find out though.

His funeral was a great ceremony held the next day. His body was put in a golden coffin. This coffin was placed into first a silver and then an iron case and was so buried.
Attila wanted to sleep without being disturbed by anybody. He had bequeathed so.

Therefore, the people who dug his grave and buried him were killed at that place by shooting with arrows. Then the riverbed of a nearby stream was changed. Water was made flow toward another direction, probably on the new bed over the grave. Thus, the final wish of the great conqueror was fulfilled.

Unfortunately, the location of his grave is still not known...

Feramez,

  I'm just curious to the physical look of Attila. Never seen a skitch of his face. Your link about Attila the Hun had this picture:

I find it little distorted from our expectation as his Hunnic origin. He looks here more like a Medditerranean or a European.  

 Wikipedia has this more realistic description of his physical appearance:

http://en.wikipedia.org/wiki/Attila_the_Hun - http://en.wikipedia.org/wiki/Attila_the_Hun

The main source for information on Attila is Priscus, a historian who traveled with Maximin on an embassy from Theodosius II in 448. He describes the village the nomadic Huns had built and settled down in as the size of the great city with solid wooden walls. He described Attila himself as:

"short of stature, with a broad chest and a large head; his eyes were small, his beard thin and sprinkled with gray; and he had a flat nose and a swarthy complexion, showing the evidences of his origin."

Attila's physical appearance was probably most likely that of an Eastern Asian or Mongolian type, or perhaps a mixture of this type and the Turkic peoples of central Asia. Indeed, he probably exhibited the characteristic Eastern Asian facial features, which Europeans were not used to seeing, and so they often described him in harsh terms.

Atli.
From an illustration to the Poetic Edda.

But the guys who murdered the funeral party would know where he was buried or were they executed too.

i think feramez is right about his tomb. because  after a perfect turanic leader dies, putting him in a golden and silver tomb is a tradition (like in the example of Genghis Khan) and after burying, the soldiers who bury kills each other....