The world-famous Boldt Castle on Heart Island is a must-see in the Thousand Islands. Uncle Sam Boat Tours and Clayton Island Tours provide guided tours to Boldt Castle and Uncle Sam Boat Tours runs regular return trips so you can spend as much time at the castle and on the island as you wish!

Clayton Island Tours provides beautiful and more intimate boat tours and offers the only public tour to Rock Island Lighthouse on Rock Island. This glass-bottom boat tour will teach you all about the St. Lawrence River and its creatures. You can purchase lunch or bring your own to picnic at Rock Island, tour a lighthouse, and take your shot at the scavenger hunt on the island (it's great for littles!).

Clayton has a beautiful downtown area to visit, walk along the St. Lawrence River, and has plenty of great restaurants. While you're there, you may want to visit the Antique Boat Museum which holds over 320 unique boats and thousands of related artifacts and archives.

The Sackets Harbor Battlefield State Historic Site highlights the area's role in the War of 1812 and offers exhibits, outdoor signs, guided and self-guided tours, and a restored 1850's Navy Yard and Commandant's House. Living history demonstrations feature guides dressed in military clothing of 1813 to reenact the camp life of the common soldier.

Walk the American Span of the Thousand Islands Bridge! The walkway is about 1-mile long and provides a scenic view of Clayton and the Rock Island lighthouse. Parking is available at the 1000 Islands Welcome Center located at the mainland end of the bridge. Visit the Welcome Center to see highlights of the region and shop the seasonal market.

A 9- mile stretch of paved trail converted from an old railroad bed runs along the Black River and connects Black River and Watertown. Start at the Black River Trailhead for views of the Black River and its rapids and head east toward Watertown (or do it in reverse!). There are multiple trailheads with parking if you only want to walk, run, or bike portions of the trail.

A reliable flow of water released from dams high in the Adirondack Mountains surges into the Black River Gorge, plunging over ledges and boulders. The narrow gorge constricts the water, increasing its velocity and creating major rapids. Adirondack River Outfitters offers whitewater rafting through 14 major sets of Class II-IV rapids.

The Thompson Park Zoo has animals that are all native to New York State. See the mountain lion, visit the butterfly house, or see what a bald eagle's nest is like. This zoo only takes a couple hours to visit.

The Jefferson County Historical Society Museum is housed in the historic Paddock Mansion in downtown Watertown, which is listed on the National Register of Historic Places. The museum contains both Paddock family and local history exhibits spread throughout three floors and within three outbuildings. The museum includes Kinne Waterwheel and Victorian lifestyle exhibits. Outdoor exhibits include the Early American Barn, Pioneer Cabin, and One-Room Schoolhouse.

Westcott Beach has a large, sandy beach along Lake Ontario. It is a popular area for swimming and fishing and also has campsites. The park also has a playground, picnic areas, and walking trails.

This park is known for its trails along Lake Ontario with limestone cliffs up to 80 feet (24 m) high. The property was previously used by the U.S. Armed Forces and was known as the Stony Point Rifle Range. Remnants of the site's military history are still there today. The property was later used as a cattle ranch and then by Robert G. Wehle, an avid conservationist, sculptor and breeder of English pointers. The park features trails for hiking and mountain biking, picnic areas, a playground, tennis and pickleball courts, and beach and fishing access.

Wellesley Island State Park is a popular camping destination and has a sandy beach for swimming. The Minna Anthony Common Nature Center has educational displays and miles of shoreline, open granite outcrops, and walking trails. One special feature of the nature center is the 1/4-mile accessible trail that has access to picnic tables and the butterfly house. In July and August, a 16 passenger Voyageur Canoe program leaves the docks of the nature center, touring Eel Bay.