The retired ocean liner, which has been moored in Long Beach since 1967, is getting a much-needed overhaul, too.

And changes are planned for another tourist site, the Aquarium of the Pacific. An expansion there, expected to be completed by early next year, will give this attraction an additional 29,000 square feet that will include a new area for exhibits, an art gallery and an “immersive theater.”

Howard Kozloff, a managing partner of Agora Partners, an urban real estate advisory firm based in Los Angeles, said Long Beach “was wise to invest in its public spaces, like the aquarium and Queen Mary Island.”

“There’s a big realization that cities have to market themselves, so they need to provide those kinds of spaces,” Mr. Kozloff said. “Having active and vibrant public spaces is a way to differentiate yourself from your competitors.”

City officials are also quick to point out Long Beach’s comparatively lower real estate prices, its temperate climate, its waterfront and its proximity to international airports.

“It’s an affordable alternative for office and residential, compared to Orange County and L.A.,” said Michael Moskowitz, a managing director of Ensemble, which has had several developments in the city and has plans for more.

Ensemble’s new residential projects will be geared toward professionals working in the area, he said. Each will offer a mix of unit sizes, from studios to three-bedrooms, with ample parking and close access to the commercial center. Its 94-unit Serenade Modern Flats, for example, is near the new civic center, while the Sonata Modern Flats is across from the convention center.

“I don’t think we’ll have much trouble renting,” Mr. Moskowitz said.