Online social networks (OSNs) have demonstrated potential for enabling older adults to remain socially connected and for counteracting social isolation and loneliness. With older adults preferring to age in place, their local community and neighborhood gain in importance. Online neighborhood social networks (ONSNs) are a novel type of OSN aimed at connecting local communities by facilitating social interaction, information sharing and peer support among neighbors. With a focus on trust and privacy, local relevance and integration with local organizations and institutions, they might be particularly well suited for the needs of older adults. We investigate the relationship between older adults and ONSNs by analyzing usage data, an online survey and interviews with users of an ONSN active in two urban neighborhoods in Germany. Our findings show that the case ONSN was successful in facilitating communication between neighbors and in promoting participation in community life for older adults.