The tiny community of Pacoima, at the north end of Los Angeles, suffers from nearly every imaginable obstacle to a healthy urban environment. That means, for starters, lead paint, freeway traffic, airports, landfills, diesel trucks, chemical manufacturing, power plants, heavy industry, and overcrowding. It also means the linguistic and cultural differences that have historically defined the largely Latino community — and separated it from potential allies.

These days, that gulf is narrowing. Through the efforts of Pacoima Beautiful, a nonprofit organization of Pacoima residents and their allies, the three-square-mile community is working with elected officials to clean up its environment. At the same time, the group is empowering Pacoima residents to organize internally, pairing former gang members with artists to paint murals, and training community mothers to educate fellow citizens and area doctors about the health hazards of pollution.

In this virtual walking tour, Marlene Grossman, above, and two other leaders of Pacoima Beautiful show that this once-beleaguered neighborhood is truly becoming beautiful — both as a place to live, and as a model of effective community organizing.

Like many tribal lands across North America, the Sokaogon Chippewa reservation in Northern Wisconsin faces environmental perils that threaten not only the land, but also the livelihood and culture of the people who live on it. The Sokaogon spent close to three decades battling one of those perils: the proposed reopening of a nearby zinc and copper mine. In 2003, thanks in large part to the efforts of environmental director and tribal council member Tina Van Zile, the tribe joined forces with the neighboring Forest County Potawatomi to end the battle — by buying the mine.

Rich with casino profits, the Potawatomi paid cash for their half of the $16.5 million purchase. The Sokaogon, one of the smallest and poorest tribes in the U.S., have tried a wide variety of fundraising efforts — from selling commemorative mine borings to auctioning off rifles — to raise their share of the bill, which comes due this April. In this virtual walking tour, Van Zile introduces us to her tribe and to the land they are trying to protect.

Donate to help the Sokaogon tribe protect the Wolf River.

New York’s South Bronx was once a getaway for the rich; now the defining landmarks of the community are power plants, landfills, and parking lots. Where some might see hopelessness, though, resident Omar Freilla sees opportunity. Freilla founded Green Worker Cooperatives to salvage reusable materials from trash and demolition waste, creating a neighborhood that is healthier both environmentally and economically. In this virtual walking tour of his community, Freilla discusses his vision of creating hundreds of jobs out of the abundance of “things that nobody else wants.”

In 1977, a factory in Columbia, Miss., that had been manufacturing Agent Orange was rocked by an explosion. The owner, Reichhold Chemical Inc., shuttered the facility and abandoned or buried thousands of barrels of toxic waste near the water supply of the predominantly poor, African-American neighborhood where it had operated; flooding and leaks followed. In this virtual walking tour, Columbia activist and evangelist Charlotte Keys, founder of Jesus People Against Pollution, describes life near the plant and her fight to win justice for her community.