I run a museum in the middle of a vibrant downtown, with a big sign and banner outside. We get good press and have thousands of local enthusiasts. But every day, many people walk through the lobby quickly and unseeing, using it as a pass-through from one part of town to another. The most common thing we hear from people passing through? “I never knew what was in here.”

People to whom the museum is relevant—people who already have keys to the experiences we offer—see the museum as an open room full of art and culture. But for outsiders, the museum is one big question mark. Maybe worth checking out. Maybe not. It is a room with a locked door. To some, the door is intriguing. To others, dull. A few on the outside feel confident that the room holds all that they desire—if only they can find the right key to the door. But most people pass by the museum unseeing, unperturbed.

When our institutions’ offerings are too opaque, or require too much effort to access, we become irrelevant. Our doors aren’t just hard to access. For most people on the outside, the doors don’t even exist.

Invisible doors are not just the hallmark of underground gambling parlors and exclusive nightclubs. Invisible doors are everywhere. At Balboa Park, a cultural park in San Diego boasting 29 performing arts organizations, museums, and cultural attractions, a 2007 study showed that many park visitors had no idea what happened inside the buildings in the park (i.e. the art venues). They experienced the park as a park. Balboa Park was relevant to them as a place to play and socialize outdoors. The buildings were not relevant to their experience, so people filtered them out.

People can only survive in an information-dense world if we pick some things to focus on and others to tune out. Try making a list of all the businesses on a block you know well. Go out to the street with your list. What did you miss? The gymnastics center? The liquor store? The law office?

Any door will always be invisible to some. There will always be some people who pass by your place unseeing, uninterested, unable to engage. That’s fine. The goal is not to open doors to everyone.

But if the people you seek to involve—the people you talk about in meetings and ardently wish for—can’t see your doors, then you have a problem. It’s not a problem that can be solved by opening your existing doors a little wider. You need to find a way to build new doors, based on their values, that fit their keys.

That’s what Betty Reid Soskin is trying to do in the National Park Service. The oldest park ranger in the National Park Service, Betty is an interpretive ranger at the Rosie the Riveter World War II Home Front National Historical Park in Richmond, CA. Her park, like others across the country, boasts huge attendance, but the people walking in the doors are not reflective of the public beyond its gates. Urban people and people of color are underrepresented in national parks as visitors, volunteers, and employees.

Betty is African-American and proud of it. She does what she can to open doors into national parks for other people of color, both as places to visit and places to build a career. Her key is her park ranger uniform. She doesn’t just wear it when she clocks in at the park. She wears it in the streets of Richmond and the East Bay. She claims the uniform of the National Park Service, not just for herself, but for other people of color too. As she puts it: upon being seen on the streets, in an elevator or escalator, I’m announcing a career path to children of color.”

But a key only works if people can see the door. One evening, Betty was on her way home from her job when she stopped at the grocery store to pick up a few things for dinner. Another customer—a black woman, like her—asked politely if Betty worked at the prison nearby. After a moment of surprise, Betty explained no, that her uniform was that of a park ranger. And then she went home.

At the time, Betty was amused—smug even—at this momentary reminder of the limitations of others’ experiences. But the anecdote grew heavy in her mind in 2015, as newspapers filled with stories of police violence against African-Americans. She encountered with distressing frequency the ugly connotations of officious uniforms in her community.

Betty thought often about her unknown friend from the grocery store. The National Park Service uniform held no meaning for her. She didn’t see it as a key to history and nature. She could only map it to a room of which she was aware: that of the prison system. Rangers weren’t relevant to her. Prison guards were.

We don’t always choose what is relevant to us. We don’t always choose what doors we see. The world chooses—in ways both beautiful and hideous, based on circumstance as much as individual will. It takes an activist like Betty, someone with incredible force of will, to open new doors and pioneer new pathways of relevance.