Riverhead sits where Long Island begins to split into the North Fork and South Fork. It is the seat of Suffolk County, but it feels less like a courthouse town than a practical gateway to eastern Long Island: wineries to the east, outlet shopping near the expressway, and family attractions clustered around the Peconic River.
The town includes Riverhead hamlet, Aquebogue, Jamesport, Calverton, Baiting Hollow, and other small communities. That spread-out geography matters. You will want a car if you plan to visit beaches, wineries, farm stands, or the parks along Long Island Sound.
Riverhead is not as polished as the Hamptons and not as pretty as the smaller North Fork villages. Its strength is usefulness: it has the aquarium, the water park, the theatre, the outlets, and enough restaurants and tasting rooms to make it a good eastern Long Island base.