What are your geographic extremes

[retromike22]

(The furthest place you have visited in each of the four cardinal directions)

Northernmost: Mammoth Hot Springs, Yellowstone National Park, Wyoming.
Southernmost: Tombstone, Arizona.
Easternmost: Washington D.C.
Westernmost: Muir Woods National Monument, California.

[FEMA Camp Administrator]

Northernmost: Michigan's Upper Peninsula
Southernmost: St. Louis, Iowa
Westernmost: Like, what, Dubuque, Iowa?
Easternmost: Eh... Somewhere in Michigan?

[retromike22]

Northernmost: Michigan's Upper Peninsula
Southernmost: St. Louis, Iowa
Westernmost: Like, what, Dubuque, Iowa?
Easternmost: Eh... Somewhere in Michigan?

You've never gone to Canada?! It's like, right there.

[MaxQue]

N: Chisasibi, Northern Quebec
S: Niagara Falls, ON
W: The westernmost point on the highway to Niagara Falls, so probably around Hamilton, ON
E: Gaspé, Quebec.

[dead0man]

N:Sault Ste. Marie Canada
S.Miami
W.Las Vegas
E.Albany NY

[SUSAN CRUSHBONE]

westernmost: crater lake, oregon
easternmost: kalmar, sweden
northernmost: kalmar, sweden
southernmost: cozumel, mexico

[Mr. Morden]

This same question was posed in this thread in 2013:

https://uselectionatlas.org/FORUM/index.php?topic=178600.0

I haven't had any new extremes since then, so I'll copy/paste that answer…

North: 53 N (Manchester, UK)
South: 43 S (Hobart, Tas, Australia)
East: 175 E (Auckland, NZ, though if you exclude airport layovers, then 153 E (Gold Coast, Qld, Australia)
West: 123 W (Victoria, BC)

Of course, measuring it like this is kind of problematic.  Note that I said "on land".  The farthest north I've actually been would have to be when I was in a plane, presumably either on a Philadelphia-Manchester flight that I made in 2007, or the London-Chicago flight in 2011.  Because of the mapping of great circles onto the globe, those intercontinental flights take you farther north than either the departure or destination city.

And of course, trying to define east-west is arbitrary, since I've crossed the International Dateline by plane many times.  When I go back to the US, I do it by going east, not west.  So in that sense, it's kind of strange to say that I've never been west of Victoria.

[Torie]

Hong Kong to the east, Kauai, Hawaii in the west, Edinburgh, Scotland to the north, and Phuket in southern Thailand to the south. I've never been south of the equator. Oh,  I forgot I had a plane refueling in Iceland (don't want to attempt spelling the name of the capital city). So put that down as the northernmost sally by me - sort of. 

[muon2]

Thanks to Morden I'll also copy and paste.

North: 56.7 N (Montrose, Scotland)
South: 27.8 S (Florianopolis, Brazil)
East: 37.8 E (Moscow, Russia)
West: 122.9 W (Sonoma County, CA)

I should set a new western limit this summer with plans to go to NW WA and Victoria BC.

[Mr. Smith]

Westernmost: Sunset Beach, Oahu, Hawaii
Southernmost: Diamond Head, Oahu, Hawaii
Northernmost: St. Andrew's, Scotland
Easternmost: Prague,Czech Republic

[Јas]

N 64.3° (Þingvellir, Iceland)
S 34.4° (Cape of Good Hope, South Africa)
E 38.7° (Addis Ababa, Ethiopia)
W 73.9° (New York, USA)

Unchanged as yet - though edging further east might happen in the next year or two.

[Zanas]

Since I'm really bored :

Northernmost : Gullfoss, Iceland, 64.341873 N
Southernmost : Crossroads outside Lumsden, NZ, 45.716506 S
Easternmost : Wellington, NZ, 174.785399 E
Westernmost : Sausalito, CA, USA, 122.487602 W

Lowest : I would guess somewhere on a polder in the Netherlands, probably -5 or 6 m.Ramsar, Iran, Caspian See coast, -28 m.
Highest : Klein Matterhorn, Switzerland, 3883 m (highest European accessible point via transportation : telepheric and lift)

Craziest : Syrian-Iraqi border east of Deir-ez-Zor in the summer of... 2003.

[Donerail]

North: Bangor, ME
South: Key West, FL
West: San Francisco, CA
East: Bar Harbor, ME

[The Free North]

Northernmost: Anchorage, AK
Southernmost: Kangaroo Island, Australia
Westernmost: Honolulu, HI
Easternmost: Sydney, Australia

[Snowstalker Mk. II]

Northernmost: Montreal, QC
Easternmost: Montreal, QC
Westernmost: Pittsburgh, PA
Southernmost: Cape Hatteras, NC

[rpryor03]

North: Niagara Falls, Canada
South: Nassau, Bahamas
West: Salt Lake City, UT
East: Rome, Italy

[Arturo Belano]

Northernmost: Chicago, IL
Easternmost: New Haven, CT
Westernmost: Denver, CO
Southernmost: Puerto San Jose, Guatemala

[ilikeverin]

Latitude: 18.4 N (Ocho Rios, Jamaica) to 55.9 N (Edinburgh)
Longitude: 122.4 W (San Francisco) to 8.7 E (Frankfurt)

Oh!  All four of my maxima have changed now!

Latitude: 45.0 S (Queenstown) to 60.5 N (Turku)
Longitude: 122.7 W (Portland) to 174.8 E (Wellington)

I don't anticipate any of these changing anytime soon, although there is a vague chance in the next couple of years that my furthest west spot may become something like 149.4 W (Seward).

[I spent the winter writing songs about getting better]

North: Winnipeg
West: Yellowstone National Park
South: Disneyworld in Orlando.
East: An area on the Florida coast.

And counting only where I've been in adulthood:

North: Minot, ND
West: Denver
South/east: Atlanta

[seb_pard]

Northernmost: Toronto, Canada
Easternmost: Buzios, Brazil
Westernmost: Los Angeles, CA
Southernmost: Coyhaique, Chile

[The Dowager Mod]

North: Fairbanks AK
South: Melbourne Australia
East: East of where? Ankara Turkey.
West: Same question. Tokyo since I flew west I guess.

[Hatman 🍁]

North: Somewhere over the Atlantic Ocean
East: Zutphen, NED
South: Danville, VA
West: Esquimalt, BC

[muon2]

North: Fairbanks AK
South: Melbourne Australia
East: East of where? Ankara Turkey.
West: Same question. Tokyo since I flew west I guess.

I just assume that E-W means the longitude counting those points one has been on the ground. As others have noted, flying from the US to Europe takes one quite far north, but it doesn't count unless one lands.

[Sumner 1868]

Northern: Bremerton, WA
South: San Diego, CA
East: Cheyenne, Wyoming.
Port Angeles, WA

[Хahar 🤔]

North: London
South: Singapore
East (by longitude): Hong Kong
East (relative to America): London
West (by longitude): Mendocino County, California
West (relative to America): Dhaka