In the quest to fill out your Pokedex in Pokemon GO, you have undoubtedly had to wade through countless Pidgey's and Rattata on your way to catch something a bit more special like a Hitmonchan or a Lapras.
If you happen to be in one of five cities, though, you'll have a definite leg up on your competition. The cities of LA, Seattle, NYC, Boston, Chicago, and Orlando are the best places to find the rarer Pokemon, with Los Angeles coming out on top. LA has the best mix of rare Pokemon sightings, with Dratini, Electabuzz, Hitmonlee, Chansey, Lapras, Snorlax, Porygon, Kabuto, and Aerodactyl's all making an appearance at some point or another.
The way it works is the city had to have a confirmed sighting of the Pokemon, data which was collected by using Twitter's API and finding hashtags that contained epic, mythical, and special Pokemon names. They also only considered tweets with actual footage or photographs, as opposed to just taking a trainer's word for it.
Now, just because those cities have the biggest sample size of rare Pokemon doesn't mean you can't find them anywhere else, as the other charts show.
For the 5 cities with the most rare sightings, it again included LA, Seattle, and New York City, but it also included Houston and San Jose. For Mythical Pokemon, LA and New York are great, but so are Washington DC, Indianapolis, and Philadelphia.
You can view the charts in the gallery, and hopefully this will help you on your quest to catch em' all.