If you think North Austin’s Domain and Domain Northside mixed-use developments are bustling with activity now, imagine if Amazon sets up its second corporate headquarters across from what’s known as Austin’s “Second Downtown.”

Brandywine Realty Trust, one of the biggest office landlords in Austin, is pitching its Broadmoor campus as a potential site for Amazon HQ2. Broadmoor, whose main tenant is IBM, sits across Burnet Road from the Domain and Domain Northside. Amazon already has a corporate office at the Domain.

In a proposal that had been posted online but has since vanished, Brandywine touts the 66-acre Broadmoor campus as a place where Amazon would have lots of room to grow.

“With Austin’s record-setting growth and booming economy, Broadmoor has the capacity — on a tight urban grid roughly the size of 16 city blocks — to house continuing growth in Austin’s newly emerging social and economic core,” Brandywine says.

Austin is among 238 communities vying for Amazon HQ2 and is considered one of the leading contenders. The e-commerce giant, based in Seattle, says the $5 billion project would generate as many as 50,000 Amazon jobs in the winning community — a prospect that some Austinites fear could aggravate the city’s traffic and housing woes.

Brandywine says it already has the ability to expand Broadmoor to 8.2 million square feet, with the possibility of adding another 20 million square feet. Today, the site contains a little over 1 million square feet of office space.

“Paired with Austin’s sweeping landscapes and culturally rich entertainment districts, Broadmoor is a place to find inspiration and community,” Brandywine says.

Brandywine expects the Broadmoor campus to be rezoned as a transit-oriented development by the end of 2017. Currently, MetroRail trains and Capital Metro buses serve the area.

The City of Austin says the goal of a transit-oriented development “is to bring together people, jobs, and services designed in such a way to make it efficient, safe, and convenient to travel on foot or by bicycle, transit, or car.”

In addition to Austin, Brandywine is promoting property in its hometown of Philadelphia for Amazon HQ2. Moody’s Analytics identifies Austin as the frontrunner for HQ2, followed by Philadelphia.

In 2015, Brandywine bought out IBM’s ownership stake in the Broadmoor campus, located at 11501 Burnet Rd, near MoPac. The campus encompasses seven office buildings totaling 1.1 million square feet. IBM has occupied space at Broadmoor since 1991, and was the only tenant for many years.

It’s uncertain whether Broadmoor is included in the city's bid for Amazon HQ, as details of the proposal have largely been kept under wraps.