First of all: These destinations are only worthwhile if you are on the island for a longer time and drive from the east side to the west side (or the other way around). South Point is too long for a day trip. If you're only vacationing in Kona, it can be worth the drive if you leave early. If you are on a tour of the west coast Big Islands and have already explored Kealakekua Bay and Puuhonua o Honaunau National Historic Park, you should drive south a bit on Highway 11, because then you won't be missing much at all until you arrive at the southernmost point of the entire USA. From Kona, the turnoff to South Point is between mile markers 69 and 70. From there, South Point Road takes you to the southernmost point in the U.S. After about 20 kilometers of driving along ancient lava landscapes, you'll head straight to Ka Lae (Hawaiian for "the tip"). Near Puʻu Nanaia, there is a lookout point on the highway that offers a view of the cape and the nearby wind farm.
About a kilometer east of the cape, Kaulana Ramp provides access to the sea.
It is quite incredible to think that there is nothing between South Point and Antarctica but the blue ocean.
In all likelihood, South Point is the site of the oldest Polynesian settlement in the entire archipelago, as it is closest to the Polynesian area of origin for this ethnic group - the Marquesas or Society Islands. Between 400 and 800 AD, the Polynesians set foot on Hawaiian soil. Remains of a heiau (Hawaiian temple) and other religious buildings have been found over the years, dated to 124 by the Bishop Museum in Honolulu. The ocean currents and winds are particularly strong here. In order to still be able to go fishing, the inhabitants were creative: for example, you can find metal rings hammered into the lava rock to which the canoes were tied for fishing hundreds of years ago. Nowadays, fishermen use so-called "Toy Boats" to lower their nets into the deep water. The exact southern tip is a short walk away, near the black and white lighthouse.
Watch the cliff divers shimmy back to land via rusty ladders on the rocks. If you are an adventurer, you can even dare to jump 10 meters from the cliffs into the crystal clear water. The jumps into the deep blue are allowed, but you do it at your own risk. Therefore, you should carefully watch the swell and jump only when the sea is calm. There is also a natural lava hole, like in a small cave, where you can jump in and then swim out after a few meters. At the metal ladder you have to climb back up. There is no other way. So there can be some discomfort...
On the way back we recommend a detour to Green Sand Beach. On South Point Road at the fork at Milemarker 10 take the right turn and drive past the Visitor Center to the very end of the road. There you can park for free. From here, there is about a 3.5 kilometer hike to the beach, which can be very strenuous and sweaty in good weather, as there is no shade. The path is unpaved and sometimes splits into several stretches. You can't go wrong, though, because all sections lead to Green Sand Beach. A small path leads down. Here you will find a green-black sandy beach of about 1300 square meters, which exists only once in the entire archipelago. The green color of the beach is due to a mineral called olivine, which was finely washed into this bay by the tides as a result of volcanic activity. When the sun shines, you lie here on a gemstone beach that sparkles greenish in the sun. A very special experience! You should also swim here only in calm seas.
Attention: Both South Point and Green Sand Beach are free of charge. Often locals claim that a toll has to be paid. Don't get confused and insist on free access if necessary!
Or you can rent a jeep, so that you can save yourself the tedious walk. You can use it well on Big Island (among other things for the ascent to Mauna Kea, Waipio Valley and here). Without a jeep you have no chance at these 3 sights and risk a broken axle!