Sault Ste. Marie holds the title of Michigan's oldest city. But its true claim to fame is an engineering marvel that connects Lake Superior with the lower Great Lakes.

The port town of 15,000 is home to the Soo Locks, one of the world's greatest manmade structures. The locks allow ships to bypass the St. Marys River and the 21-foot drop between Lake Superior and Lake Huron.

Visitors to the area can watch the ships work their way through the channel from an impressive multi-level observation space in front of the Soo Locks Visitors Center (312 Portage Av.; 1-906-632-7020; open mid-May through mid-October). If the weather is nice, head to the top level, which is an open-air balcony overlooking the locks. On cooler or wet days, visitors can stay on the lower levels and view the ships from a glass-paneled observation space.

To experience the locks firsthand, take the Soo Locks Boat Tour (; 1-800-432-6301). The two-hour cruise brings you through the locks right alongside the freighters. Once you've passed through the locks, your ride continues to the International Bridge and into Canadian waters. (You do not need to carry your passport on the boat, though.) The boat tours, which open for next season in May, come in a variety of options including sunset cruises.

Be sure to spend some time at the free visitors center, which outlines the history of this engineering marvel. There, you'll learn that in the late 1700s, a navigation lock was built for small boats on the Canadian side; the lock was destroyed in the War of 1812. In 1853, the Fairbanks Scale Co. undertook the massive challenge of building a lock allowing ships to travel between Lake Superior and the other Great Lakes. The only catch as part of the deal: The state of Michigan set a two-year deadline. By May 31, 1855, two 350-foot-long locks were complete. Today, two operating locks out of a total of four allow the passage of about 10,000 ships per year.

Getting a good view

Although the visitors center isn't open year-round, the Soo Locks Park is. You'll find it surrounded by souvenir shops reflecting the locks' place as an international tourist attraction. If you need a sweet treat, stop at Fudge Du Locke (319 W. Portage Av.; 1-906-635-5033) and watch workers concoct a variety of flavorful fresh fudge -- and grab a sample.

For panoramic views of the city, along with neighboring Canada, be sure to check out the Tower of History (501 E. Water St.; 1-888-744-7867; The tower, which sits 210 feet above the Sault Ste. Marie skyline, dates to 1968. It was initially built by the Catholic Church to pay tribute to the missionaries who first made their way there. The tower also showcases American Indian history. The city was built and occupied by Native Americans for more than 500 years, up until 1668, when Father Jacques Marquette founded a mission making the town the oldest European settlement in the Midwest.

'Twin' cities

After a day of sightseeing, consider an evening drive to Sault Ste. Marie, Ontario. You'll need to pass through customs to cross the nearly 3-mile-long International Bridge. The bridge, which crosses the St. Marys River before heading into Canada, provides great views of both countries.

Sault Ste. Marie, Ontario, has a population of almost 75,000. Its size means more dining options and boutiques than its U.S. counterpart. Station Mall (293 Bay St.; 1-888-277-6880; is the region's largest shopping center while nearby Queen Street offers a variety of specialty shops. The city, which has a European feel, has also done a nice job of preserving its rich history.

Beth Probst is a freelance writer in Iron River, Wis.