Reimagining the National Mall

The National Mall - worn from wear - is seen from the top of the Washington Monument facing the Capitol in Washington, D.C., Tuesday, July 14, 2009. The National Mall is the most-visited national park in the U.S., receiving more than 25 million visitors per year - more than Yellowstone, Yosemite and the Grand Canyon combined. And in the words of the Trust for the National Mall, it has been loved to death.

AP/Nelson Byrd Woltz Landscape Architect & Paul Murdoch Architects

It has been 36 years since major restoration work has been done on the National Mall, and so The Trust for the National Mall is sponsoring a design competition to revamp three overused and neglected areas of the public space. Left: An artistic rendering of a proposed renovation at Constitution Gardens.

Balmori Associates + Work Architecture Company

The Trust for the National Mall, a nonprofit group seeking to raise money and support to restore parts of the National Mall, is unveiling final design concepts for three parts of "America's front yard" - areas overused and neglected for years near the U.S. Capitol, the Washington Monument and Constitution Gardens. They unveiled designs from the finalists in the competition and are inviting public comments on the proposed renovations.

Left: At the Sylvan Bowl, near the Washington Monument, Balmori Associates + Work Architecture Company designed a hemispherical grass bowl for a theater, centered on a circular stage." Its" amphitheater for the masses" represents an American democratic ideal.

Donald Stastny, an architect advising the Trust for the National Mall, is surrounded by boards depicting proposed designs for the National Mall during an interview in Washington April 5, 2012.

People walk and ride bikes next to cherry trees in the Washington Monument grove on April 2, 2010 in Washington, D.C.

In Diller Scofidio Renfro + Hood Design's concept for the Sylvan Theater the landscape is figuratively "peeled up" to create a structure serving as an outdoor theater - a confluence of nature and artifice.

Diller Scofidio Renfro + Hood Design's concept for the Sylvan Theater.

Balmori Associates + Work Architecture Company's concept for the Sylvan Bowl Theater.

OLIN + Weiss/Manfredi see a "sequence of settings" connecting the Washington Monument with the Tidal Basin, and envision what it calls a "new performance landscape."

OLIN + Weiss/Manfredi's concept for Sylvan Theater.

The bandshell of Michael Maltzan Architecture + Tom Leader Studio's Sylvan Theater is a flexible armature designed to retract in winter, and open in the spring, like the cherry blossom trees, forming a canopy over the stage.

A multipurpose facility by Michael Maltzan Architecture + Tom Leader Studio for the Sylvan Theater, featuring ticketing, connections to Monument Lodge, and a cafe.

A view of Constitution Gardens pond on the National Mall on June 5, 2006, when schoolchildren cast their lines during the "Fishing on the Mall," event to celebrate National Fishing and Boating Week. More than 300 youngsters from Maryland, Virginia, and the District of Columbia fished for bluegill, largemouth bass and yellow perch.

People pose with the basket of an American Civil War-era observation balloon during a demonstration on the National Mall June 11, 2011 in Washington, D.C.

A "museum without walls" is OLIN + Weiss/Manfredi's description of his plans for Constitution Gardens as "a dynamic and sustainable" urban park.

OLIN + Weiss/Manfredi's concept for Constitution Gardens is "a model for integrating social activity and green infrastructure into our national cultural landscape."

Nelson Byrd Woltz Landscape Architect + Paul Murdoch Architects's plans for Constitution Gardens.

An artist's rendering of Nelson Byrd Woltz Landscape Architect + Paul Murdoch Architects' redesign of Constitution Gardens.

Rogers Marvel Architects + Peter Walker and Partners redesigns the topography of Constitution Gardens to reduce noise from nearby traffic, and improve water quality, while providing a grand park entrance.

Rogers Marvel Architects + Peter Walker and Partners' concept for Constitution Gardens.

Andropogon + Bohlin Cywinski Jackson also redesigns the topography of Constitution Gardens to create a "healthy and vibrant" lake at its center.

Andropogon + Bohlin Cywinski Jackson's concept for Founders' Terrace at Constitution Gardens.

THE CANADIAN PRESS IMAGES/Sean Kilpatrick

The view from Capitol Hill down the National Mall towards the Washington Monument in Washington, D.C., Thursday, Feb. 3, 2011.

Gustafson Guthrie Nichol + Davis Brody Bond's concept for Union Square, unifying the public plaza, monumental pool and botanical garden.

Gustafson Guthrie Nichol + Davis Brody Bond's view for Union Square.

Diller Scofidio Renfro + Hood Design's concept for Union Square takes into account the natural history of the site's native wetlands, where water is a primary element.

Diller Scofidio Renfro + Hood Design's concept for Union Square expands upon the original layout, extending Union Square - presently an "island" isolated by traffic - into adjacent spaces North and South.

Interactive fountains are a feature of the Union Square redesign by Pei Cobb Freed & Partners + Workshop: Ken Smith Landscape Architect.

Pei Cobb Freed & Partners + Workshop: Ken Smith Landscape Architect's concept for Union Square.

Snohetta + AECOM's would unite the isolated Union Square with its surroundings, including vernal gardens, trellises, the Ulysses S. Grant Memorial, a reflecting pool, and a new sloping platform extending towards the West Mall.

Snohetta + AECOM's vernal gardens for Union Square.

The finalists' designs will be displayed at the National Museum of American History's Lemelson Hall through April 15, and are also viewable online. The Trust for the National Mall will announce the winning designs in May.

For more info:
Reimagining the National Mall
National Mall Design Competition
The Trust for the National Mall

By CBSNews.com senior editor David Morgan

CBS News 24/7