When I visited Beijing I mistakenly referred to the exercise grounds in a park as kid's playgrounds... turns out they're actually there for seniors to use and they sure do... crowded every day. Sidewalk food vendors along every street also promote socializing.

Chinese friends of mine would like to bring their parents from China, but they're having nothing to do with it. They don't want to lose the active social network they have at home.

Every evening when it's warm enough to not wear a thick coat, every park has people of all ages dancing, but mostly old people. In the cities I've been to, there are parks in every neighborhood. They have exercise equipment and places to gather and play games or do shared hobbies (kicking a shuttlecock, whip-cracking, etc). Being old in China is incredibly lucky.