This along with the countless other sites and museums in Rome makes for a city with many things to do during a long vacation. Many of these sites as well as others are available to as a guided tour giving you the chance to hear much information about what you are seeing as well as being able to ask questions. Other cities in Lazio having many things to do include Rieta, Viterbo, Frosinone, Tuscania, Terracina, and Bolsena, All of these cities have their share of Roman ruins, Museums and beautiful countryside's to see but in a small less crowded environment.
Sightseeing isn't the only thing you can do in the region, there are many popular camping and hiking areas offering some very scenic vistas. If you aren't interested in camping and don't want to go to the beach by the sea there are several very nice lakes to the north of Rome. Lake Bracciano and lake Bolsena seem to be the most popular and have some nice lake resorts as well as lake Vico which is a smaller lake and is about half way between the two larger lakes.
Overall the Lazio region is a very popular travel destination with good transportation and many things to see and do where you can easily spend your entire vacation visiting. With over 140 museums and galleries in the region half of which are in Rome to help the planning of your vacation here is a list of most of the museums and galleries in the region and the cities there are in or near.
It would be great if I could provide information and a link for every city and every museum in each region but not many if any websites could really do that. With that in mind if you want information on any place you find interesting that you found here you could try wikipedia travel which has thousands of people from all over the world providing them with information. Also don't forget to come back to do your hotel search once you have picked out the city you want to visit or just bookmark the links page.
Hopefully the information provided will help you to better decide where in Italy you may want to go and by using the Planning your Italian vacation page will make planning your Italian Vacation a breeze.