There's no shortage of beautiful ornate water works and fountains in Rome, even the small fixtures…read morethat are just meant as water spots for people and pets are works of art. As I learned, the fountains of Rome are not just for show, they're an important part of the area water network. Rome is fed by one of the most potent mountain spring aquifer sources in the world, pumping 525 MILLION GALLONS a day. The pressure on piping for that kind of quantity is immense, and reliable outflows are needed in addition to the water use privately. Hence the many fountains and watering points around Rome, all fit for drinking straight from the tap or filling your most handy water bottle.
Trevi fountain is easily one of the most ornate however, giving you that feeling of it being an exquisite pool for the gods. It has a almost a grotto-like feel, with the original stonemasons opting to use large unworked boulders as part of the landscape where they affixed their finely sculpted masterpieces. The square that surrounds it is just jam packed full of people, so unless you are tall like me, be prepared to work your way in for a good shot. If you are looking for refreshment, you'll be waiting a long time here. There are smaller water sources nearby to splash your face and fill your bottle.
While you could spend months trying to explore all the fountains of Rome, if you just have a couple days, this one if the must see. It lives up to its reputation in every way.