In Book 3 of the Iliad, where is the duel fought?

In Book 3, there is a duel between Alexandros (also known
as Paris) and Menelaos.  The duel happens in an area in the open space between the
armies of the Trojans and the Achaians.

At the beginning of
Book 3, the two armies are about to fight a battle.  As they march rapidly towards one
another, Paris comes out of the Trojan side as their champion to challenge any Achaian
to a duel.  Menelaos accepts the challenge.  After some negotiations between the leaders
of the two sides, a space is measured out and the two men fight in that area between the
two armies.