Symphony Woods in downtown Columbia is a patch of nondescript land used mainly as a pathway for the tens of thousands of people who attend concerts at Merriweather Post Pavilion each year.

But a new development plan calls for a dramatic makeover designed to bring more activity to the 36-acre property. Among the architectural features is the Butterfly building, a sweeping structure of mirrors and glass that would include an art gallery and large decks. An outdoor amphitheater known as the Chrysalis would have a tent-like covering of a lightweight metal.

And then there is the Caterpillar, described by landscape designer Martha Schwartz as "a great big worm kind-of tube" stretching east-west across the park as a boundary between Merriweather and Symphony Woods. The tube, which would be wired for irrigation and electricity, would be covered in live plants.

The plan, scheduled to be unveiled at community meeting Monday evening, was developed by the Inner Arbor Trust, a corporation created in February to develop and fund the park. It assembled a six-member international design team to transform the site. Ultimately, the plan would have to be approved by the Howard County Planning Board.

Sign up to receive our free daily email newsletter: Columbia Today

"Merriweather is only used 13 percent of the year," said Michael McCall, president of the trust. "This idea makes Merriweather more than just a concert venue, but a cultural development."

The announcement coincides with a resurgence of downtown growth in Columbia, a planned community that opened in 1967, the same year as Merriweather. An apartment community is being built next to the Columbia mall, a Whole Foods and fitness center will occupy the former Rouse Co. building on the lakefront and the mall is adding an outdoor wing with retailers and restaurants.

But the comprehensive changes proposed for Symphony Woods — and later Merriweather — may be the most ambitious of them all.

Included in the first phase of the plan for 16.5 acres bordered by Little Patuxent Parkway and South Entrance Road is the amphitheater, an approximately 200-foot long "picnic table" sitting area, a maze, pathways and a boardwalk.

"Merriweather and Symphony Woods can be for Columbia what Central Park is for Manhattan and Grant Park for Chicago — an international destination and a source of energy and pride," County Executive Ken Ulman said in a statement. "We need to think big about Merriweather and Symphony Woods. That's what is happening. We need to move forward, and continue the momentum."

Ulman, a Columbia native and 2014 Democratic candidate for lieutenant governor, has already pledged $5 million in county funds for the project.

McCall declined to put a price tag on the project, but estimated it could cost approximately $30 million using public and private funds.

McCall said he hopes the site development plan will be approved by county agencies next summer, and that construction would begin on the amphitheater in the fall.

The Trust's master plan, which it is calling Merriweather Park, also includes an arts village on the eastern side of Symphony Woods and a cultural arts center called the Black Barn, which would be built on Merriweather land and include a ballroom-type venue, two theaters, a restaurant, art gallery and new park entrance.

The Black Barn concept, which McCall said might not be built for a decade, would be constructed parallel to the Merriweather stage and built into the berm behind the lawn.

McCall said the Trust has taken the county's mandate to create a comprehensive neighborhood seriously, which is why the proposed redevelopment includes the renowned concert venue, which is owned by Howard Hughes Corp.

Howard Hughes, which is mandated by the county to redevelop the concert venue before turning ownership over to a downtown arts commission, is a spinoff corporation created by Mall owner General Growth Properties and the top land owner in downtown Columbia.

John DeWolf, senior vice president of Howard Hughes, said the Trust's plans are "interesting" and that he "applauds their effort."

Said McCall: "We hope to influence where Merriweather is going and hope to work out an agreement to develop this."

DeWolf said Howard Hughes has not yet explored redevelopment for Merriweather.

"We do have to spend some money, which we are prepared to do, but it's a ways off," DeWolf said.