What about an Adult Playground?

The pos­i­tive effects of exer­cise on brain health have been demon­strat­ed in many stud­ies now. The next step may be to devel­op low-cost pro­grams in the com­mu­ni­ty that pro­vide appro­pri­ate sup­port and struc­ture for adults (espe­cial­ly old­er adults) to encour­age phys­i­cal activity.
A great exam­ple of such pro­gram is The Adult Play­ground in Bei­jing, Chi­na (Dhand et al., 2010):

Half a foot­ball field large, this space con­sist­ed of all-weath­er stretch­ing and strength­en­ing equip­ment such as ellip­ti­cal machines, flat bench­es, mod­i­fied leg press machines, rail­ings at dif­fer­ent heights, mon­key bars, and arm and leg rota­to­ry devices. The area was teem­ing with adults, most old­er than 60 years, who were not only exer­cis­ing but also play­ing games such as Chi­nese hacky sack (a Chi­nese game from the 5th cen­tu­ry BC) and tra­di­tion­al board games.

The Chi­nese gov­ern­ment has erect­ed sev­er­al out­door adult play­ground of this type across urban areas. This seems to be a great exam­ple of a low-cost, eas­i­ly acces­si­ble, solu­tion com­bin­ing phys­i­cal exer­cise with social­iza­tion as well as cog­ni­tive exercise.