Whether you're an urban dweller surrounded by concrete or live on a cul-de-sac in suburbia, everyone does well with a bit of fresh air. National Trails Day on Saturday, June 4, reminds us of this basic fact. Starting on June 5, 1993, the American Hiking Society has encouraged people from across the United States to set aside the first Saturday in June as a chance to celebrate the nation's trails. And, as city populations continue to increase, the American Hiking Society—along with the National Parks Service—is emphasizing the accessibility of many of these meandering open spaces.

This Saturday, thousands of organizations across the country are holding events to celebrate nearby parks and trails. Participate in one near you, or just take some time to appreciate Mother Nature by hiking or biking on a local trail. Here are seven of our favorite spots for outdoor recreation, all near major urban centers and accessible by public transportation.

1. General Grant National Memorial (New York City, NY)

The General Grant National Memorial is an ideal escape from the fast pace of the Big Apple. On the banks of the Hudson River, it is surrounded by the Riverside Park with its many trails. You can spend this weekend restoring the historic grounds. MTA subway and buses stop at the memorial.

2. Couturie Forest (New Orleans, LA)

Hop on one of many RTA buses and streetcar lines to the heart of New Orleans. The New Orleans City Park includes the 60-acre Couturie Forest. Go on a family hike there Saturday, or explore its countless trails any time.

3. Red Mountain Park (Birmingham, AL)

Located in central Birmingham, the Red Mountain Park is a beacon of heritage for many residents. Serving as an iron-ore mining ground in the 1800s, this natural and historic landmark has a 14-mile trail system for visitors to trek. Access this vital green space via the BJCTA MAX transit system.

4. Presidio of San Francisco (San Francisco, CA)

Once an army post, the Presidio has been refurbished as a tourist venue. Hike scenic trails among military relics and learn about the ecology of the Bay Area. You can catch the convenient PresidiGo shuttle from downtown San Francisco.

5. Big Cottonwood Canyon (Salt Lake City, UT)

A landmark for miners heading west in search of gold and silver, Big Cottonwood Canyon is in the Uintah-Wasatch-Cache National Forest, near Salt Lake City. Visitors to this serene canyon enjoy breathtaking views of alpines. UTA offers service here.

6. Minnesota Valley National Wildlife Refuge (St. Paul, MN)

Spend this Saturday walking the plains of the Minnesota Valley National Wildlife Refuge in search of native birds. The natural grounds are filled with an assortment of wildlife and trails. Easily accessed by the MVTA transit system.

7. Capital Crescent Trail (Washington, DC)

Built on top of an abandoned railbed, the Capital Crescent Trail is just east of the Potomac River and run by volunteers. It's the perfect place to walk, bike, run, or just relax away from the rush of the city. The CCT provides directions for accessing the trail by Metrorail.