The tower was situated on the left bank of the Seine facing the old castle of the Louvre on the opposite, right bank. Originally known as the Tour Hamelin this was a cylindrical structure of approximately 10 metres in diameter. The height was around 25 metres, with a stair turret reaching higher still. Later on, the tower was incorporated into the Hôtel de Nesle, a medieval mansion. Old engravings show that there was a similar tall tower on the right bank of the Seine adjacent to the Louvre, therefore the towers may have together protected the upstream approach into the city toward the towards the Île de la Cité. Records show this other tower was at one time called the Tour de la Conférence and Tour du Coin.