Key West celebrates the fact that they are the southern most point of the Continental United States. Hawaii has the distinction of being the Southern most Point of the entire US. About 390 miles farther south than Key West. Changes in Latitude indeed.
Near south point there is a spot where you can jump off the cliff. It is not a super high cliff, but great fun for tourists feeling adventurous. CLIFF DIVING
This area also holds the Southern Most bakery in the US. I was told to go there and get the traditional pastry with the traditional filling. When I saw Sweetbread on the sign, I got a little worried. Sweetbread are organ meats. It turns out that in Hawaii it also means sweet breads, as in pastry's and breads that are sweet. They were good.
The Southern most Bakery in the US
On the way South there is an easy to get to Black Sand Beach called Punaluʻu Beach. The Green Sea Turtles like to lay there eggs here, and sun themselves.
Honest, they really are alive. 
Black Sand Beaches are not exactly soft sand beaches. The sandy portion is rough on the feet, the more pebbly parts really require shoes. 
No... Really, they ARE alive. 
Unlike Key West, this is not a super crowded spot. There is no marker, no buoy, no bars nearby.
A bit desolate. 
Those people are the only ones I saw come to the southern most point. There are more over at the area they do the cliff jumping. 
Another Beautiful day, this time at South Point.
Not far from South Point is a Green Sand Beach. There are very few of these in the world, the claim is that there are 4 in the world, but there is another one on Hawaii that I saw on the Helicopter flight. No one goes there because it is too hard to get to.
I walked the 3 miles to get to the beach. There are people with very rickety pickup trucks that will take you both ways, but I wanted to walk, at least one way. The walk was not hard, but the wind was crazy, and no shade. It was also difficult to figure out which road to take, although it didn't really matter as they all go to the same place, criss crossing on the way. The $10 truck ride back was fun, standing to keep from getting bashed around. This is definitely not a place I would want to take a nice truck. The ruts and nasty sharp rocks eat a lot of oil and transmission pans.
The "road" to the beach. 
Not exactly green, I would call it greenish.It is a steep hike down from the top to the actual beach. There is a ton of wind, and you get sandblasted with some very nasty sand. The water looked fun though.
Yup, Greenish.