It was little known until it was explored in 1884 – 1887 by Karl von den Steinen from Cuyaba. Travelling east, 240 miles, he found the river Tamitatoaba, 180 foot wide, flowing from a lake 25 miles in diameter. He descended this torrential stream to the river Romero, 1300 foot wide, entering from the west, which receives the river Colisu. These three streams form the Xingu, or Parana-xingu, which, from 73 miles lower down, bounds along a succession of rapids for 400 miles. A little above the head of navigation, 105 miles from its mouth, the river makes a bend to the east to find its way across a rocky barrier. Here is the great cataract of Itamaraca, which rushes down an inchned plane for 3 miles and then gives a final leap, called the fall of Itamaraca. Near its mouth, the Xingu expands into an immense lake, and its waters then mingle with those of the Amazon through a labyrinth of eanos (natural canals), winding in countless directions through a wooded archipelago.
Original text from 1911 Encyclopaedia Britannica