We can say that is a new challenge for people in adrenaline rush. But not everybody gets to play a tennis match at 210 meters altitude, the Annex hotel Burj Al Arab in Dubai.      Tenisman famous Andre Agassi made a demonstration on land specially arranged, but was careful to keep a low game speed, but not the other edges that delimit the space are not high. The land was originally designed as a helicopter landing place, but now has a double r...