Real estate is said to be about three things—location, location, location—and the same might be said for retirement. Where we live is a powerful determinant of our overall health and well-being in older age. But as we’re living healthier, longer lives and snowbirding to Florida no longer appeals to a new generation of retirees, the question is, where should we settle down?

Should you age in place, staying where you have your mortgage, marriage and memories? Should you downsize? Bunk in with adult children? Maybe you should consider the assurance of a continuing care retirement community? The choices are many and complex.

While utopia for retirement living remains elusive, there are key characteristics of what your Gerontopia might include. In our work at the Massachusetts Institute of Technology AgeLab and Center for Transportation & Logistics, funded in part by the U.S. Department of Transportation, we’ve developed a framework to help planners, policymakers, and developers assess the age-readiness of a community. We propose that you let AIDA—Activities, Intensity, Density and Accessibility—be your guide to assess whether your community meets both your needs and wants. The importance given to any one of these factors may be an individual choice, but each of these dimensions, in some measure, is critical to living well in older age.

Because many Americans can plan on two-plus decades of healthy life after they turn 60, retirement is likely to be for a long time. Living 20 or 30 years after full-time work demands something more than an occasional cruise or family visit. Interests, as well as your capacity to explore them, will change in later life, and an ideal community should offer a wide range of activities. Sure, there must be the places that offer what you need—housing, grocery stores, healthcare—but there should also be fun: retail places that offer regular engagement such as restaurants, cafes, and book stores, for example, and cultural outlets—theaters, libraries, museums—that add to the richness of the community and provide an incentive to keep learning for a lifetime. People who report positive well-being in retirement do far more than window-shop and sip coffee. They often work part-time, volunteer or serve as mentors. Communities with a rich range of civic, religious and social centers are inspiring at any age.

Also be on the lookout for the intensity of all these activities. Does your planned hometown offer a diversity of activities? What is the general verve of the community? If you live in an urban area, in between the cafes and curio shops, are there green spaces to walk, places to exercise, a diversity of distractions that enliven every day? Retirement once meant to ‘retire’ or to pull back from life. Today, aging well is not about finding a place to rest. It’s about living in a place that pulls and pushes you out of your rocking chair.

How close all these activities are to you brings us to density. Having necessities, access to fun, and opportunities to socialize within walking or biking distance ensures that being engaged is a daily activity, not a special trip. Moreover, that density of activities increases the likelihood of chance collisions with old friends and opportunities to make new ones, which are vital to your well-being in retirement.

But if this range of dense and intense activities doesn’t meet the test of accessibility, it may as well be a continent away. Accessibility requires that there be wide sidewalks that are easily traversed by foot, scooter or wheelchair. There should be a range of convenient public, private, and volunteer transportation alternatives that can take you to get an ice cream cone when you want it, not just a ride to the doctor’s office when you need it. Well-lit streets should allow you to feel safe both day and night. There should be benches throughout where you can chat with friends, as well as covered outdoor areas that offer protection from the weather and a diversity of street-facing public spaces that are easy to access, no matter what your physical ability may be.

There’s also a 21st-century dimension of accessibility: The age-ready community requires that everyone has easy access to digital and on-demand conveniences, which include home delivery of meals and access to such sharing-economy amenities as Task Rabbit, Uber, Lyft and other providers of transportation, home maintenance, on-demand home care providers such as Honor, and other services that make living easier across the lifespan. Twenty-somethings may have brought them into the mainstream, but they may be even more useful tools for the aging.

All these features are elements of a community that’s not just accessible for residents of every age but exceptionally livable too. Comprehensive retirement planning is about more than health and wealth. It is about planning to live longer and better. Communities that support living well in old age with an intensity and density of activities that are exciting, engaging, and easily accessible may in fact be Gerontopias. But given the active, vibrant and neighborly lifestyles that an AIDA approach to community-building can foster, they turn out not to be utopian only for the aging but for people at any age.