Trajan, AE Sestertius, Rome. 98-117 AD.

Obv: IMP CAES NERVAE TRAIANO AVG GER DAC P M TR P COS VI P P, laureate, draped bust right.
Rev: PORTVM TRAIANI, bird's eye view of the basin of the 
harbour of Porto, surrounded by warehouses, ships in the
centre. SC in exergue.

RIC II 632. 
Cohen 306v.
Courtesy of numismaticmythology.com, Jan. 2011.

The construction of an additional basin to Ostia harbor 
of Ostia is recorded on this rare sestertius. The port was 
octagonal in shape and surrounded by various warehouses. 
Trajan made improvements to the ports of Ostia,
Centumcellae and Ancona, and the representation on this 
coin has been claimed for each of these seaports by 
different authorities, but the RIC author has little doubt 
that this Portus Trajani is that at Porto, near Ostia, founded by Trajan in 103 AD.