a) A setting where it's acceptable to strike up a conversation with a stranger
b) A place not already geared towards a different purpose (i.e. a bar for hookups)
c) Filled with -- for lack of a better phrase -- people who are uninteresting to talk to. By that I mean people who aren't looking to chat, all conform to a very rote / traditional lifestyle, or generally aren't great conversationalists.
Common politeness generally means avoiding personal or possibly controversial topics with strangers, so you might have to invest the time to get to know someone.
If by interesting you mean people who enjoy the same topics of conversation as you do then pick a topic.
Figure out what people interested in that topic do, where do they go.
Go there.
take a class in some subject that is somewhat outside your comfort zone, so if you're a programmer don't take a programming class. I would recommend an art, music, or literature class. Downside, lots of uninteresting people really into those subjects can also be pretentiously annoying.
Other classes one can take that will also be healthy for you: Dance, cooking (maybe of some type that is not that well known or trendy will improve chances), Capoeira - has a generally gregarious culture and tends to have people who are not as much into the general martial arts stuff as others - especially Capoeira Angola.
However all these things probably betray my particular interests and where I might expect to find people I consider 'interesting', it's a pretty subjective quality.
Do you think at this point people might be sensing that you're bracing for boredom as you're talking to them? I don't mean to blame you but vibes are powerful and real and it takes a lot of effort to truly conceal our emotions and assumptions
And don't forget to make yourself comfortable to banter and have small talks, sometimes people complain about how hard it is to make new friends, meanwhile they are super shy, not sure how they can find one tbh :(
I think it'd will be more excited to meet random people and find out that they're interesting than you try to find them at a specific place.
Volunteering in the community you live brings a wide array of people and there’s usually downtime for talking.
-Hobby clubs. (We all have the hobby in common)
-Work conferences. (I work in tech so tech is always interesting.)
-Friend groups/activities.