Ostia Antica is possibly the most visited place in Lazio outside of Rome on account of the ease of getting to it - a rail line under the auspices of Rome metro from Magliana on Linea B.
There's an attractive area round the fort but it's the Scavi that atract people, the excavations of the old port of Rome. You may well be surprised by the extent of the remains. Oddly, ostia Antica Roman site was never reused after it followed Rome in its fall and so it provides a substantial area of a real working Roman town.
Unlike Pompeii it doesn't send messages of luxury. This makes it all the more remarkable that the baths should have been open and free to all who wanted to use them.
There are the ruins of a large hotel that was mainly frequented by workmen and sailors and the housing areas are working class. However there are some grander areas. The Theatre and the vast building called the Capitolium are pretty impressive. [edit text][editors]