SAN JOSE — A major real estate company is planning a mega office campus in downtown San Jose near the banks of the Guadalupe River, a project that could accommodate several thousand workers, municipal documents show.

The proposal visualizes a sleek, curving office complex that would approximate the contours of the river as it meanders near the Children’s Discovery Museum.

Boston Properties has proposed a development that could contain up to 1.8 million square feet of office space, the equivalent of a big regional shopping mall. If built to that size, as many as 9,000 people could work in the offices.

“You are seeing some smart money coming into downtown San Jose,” said Bob Staedler, principal executive with Silicon Valley Synergy, a land use and planning consultancy. “Boston Properties is a major company, well capitalized. They developed the Salesforce Tower in San Francisco.”

The gleaming new development would be located on South Almaden Boulevard between Woz Way and San Carlos Street and would be directly across from the San Jose McEnery Convention Center.

“The interest in downtown San Jose is increasing,” said Nick Goddard, a senior vice president with Colliers International, a commercial real estate firm. “Once the ball gets rolling, it gains momentum and gets bigger and bigger. The big money is now leading the parade.”

The wording in the application leaves open the potential for ground-floor retail or restaurant spaces, although specifics weren’t immediately available from the preliminary plans.

The campus could be 17 to 18 stories high, the planning documents indicated.

“It is too early for us to comment on this application at this time,” Helen Han, a marketing director with Boston Properties, said in an email response to this news organization.

CBRE brokers Sherman Chan, Jeff Houston and Mike Benevento are seeking tenants for the proposed offices. The new complex is aimed at attracting major tech companies such as Facebook, Google, Amazon, or Apple.

“This definitely looks like space designed for a tech company,” Staedler said. “The project will have a lot of amenities, and the look and lighting and the large floors are all attractive to tech companies.”

The South Almaden Offices proposal marks the second time in less than two months that Boston Properties has signaled a heightened involvement with an office complex that could be a game-changing development for downtown San Jose.

In December and January, Boston Properties obtained options to buy an ownership stake in the Platform 16 office campus project site, which would sprout adjacent to a different section of the Guadalupe River near the corner of Julian Street and Autumn Parkway.

Boston Properties then announced it had entered into an agreement to jointly develop the site with TMG Partners and Valley Oak Partners. That complex would total 1.1 million square feet.

A growing number of major players, including tech companies and developers, are pushing into the downtown area.

Google plans to develop a transit-oriented village of office buildings, stores, restaurants, homes and parks near the Diridon train station where 25,000 could work, including 15,000 to 20,000 of the search giant’s employees.

San Jose-based Adobe intends to expand its three-building headquarters campus downtown by adding a striking new fourth office tower at an adjacent site.

Stalwart development firm Jay Paul intends a wide-ranging redevelopment of CityView Plaza, located near the Tech Museum. Jay Paul bought that big site in 2018, paying $283.5 million.

“Boston Properties knows they are going to ride a wave for the downtown,” Staedler said. “And that wave points to the increasing urbanization and growth of downtown San Jose.”