The tower is located in Ostia along the "Idroscalo" street and was built in 1560 following the 1557 big flood when the Castle of Giulio II lost the military rule and the controlling function. It's very probable that Michelangelo realised it when he was the architect of the St. Peter's factory. Once there was an abandoned and degraded area in front of the tower, flooded in raining periods, known for the presence of the "salicornieto".
Today this area is part of a project of Environmental Reconstruction called Mediterranean Habitat Centre that is still under construction thanks to the work of the Roman Coastal Branch (Ostia) of LIPU (Italian Society for the Protection of Birds).

Lipu Ostia