As interest in historic preservation grows, more and more architects are adapting old or historic buildings for a new purpose. For example, a downtown department store can become an apartment building, or an old post office can find new life as a hotel. Both are examples of what architects call "adaptive reuse".

San Francisco's Fisherman's Wharf is one of the top tourist attractions in the United States, with an average of 12 million visitors every year. Among the sites at Fisherman's Wharf is a waterfront marketplace that was once a fruit-canning factory.

The building now houses shops, offices, restaurants and the Argonaut Hotel. "This building was used as a warehouse for the Cannery next door," said Barry Pollard, the hotel's general manager. "The goods were packed and shipped out under the Del Monte brand. It was the largest cannery in the world at one time. In 1929, the processing for Del Monte was moved to the East Bay and this building became abandoned."

Forty-five years later, the still vacant building was designated a historic landmark. It was transferred to the National Park Service and remodeled for its new use, as a hotel and visitor center for the San Francisco Maritime National Park, which occupies the ground floor.

Although the structure still has its original brick walls and enormous wood beams, the interior space was transformed into modern rooms with a nautical decor. Mr. Pollard says both the hotel company, and the maritime park benefit from the adaptive reuse.

"The rent that we pay goes directly back to the preservation of the antique ships in the national park," he said. "Our relationship with the National Park Service has given us the opportunity to display some genuine nautical and maritime artifacts such as these ship wheels. These are genuine ship wheels that are on loan to us from the park service."

The interpretive center for the maritime park features exhibits about the culture of the area, the life of sailors, and the centerpiece of the National Park - the tall ships and other sailing craft docked at the nearby Hyde Street Pier.

Park superintendent Kate Richardson says there are plans to expand the center and create a "simulated" walking tour of the park coastline within the exhibit space.

"It'll basically start at the Golden Gate, you'll walk along what is known as 'Chrissy Field,' which was at one time called 'Fisherwoman's Lagoon,'" she explained. "There, we'll tell the Native Americans' story, the Spanish exploration story, about immigration, the Gold Rush, and modern day shipping."

Although the visitor center is new, the Park has been around since 1988. And there is a lot to do there besides stop by the visitors' center. You can tour a World War II submarine, watch craftsmen restore some of the boats in the collection and even take sailing classes on one of the Park's tall ships.

Last year, four million people visited the San Francisco Maritime National Park.