Don't know if you have a car or how long you will be their but if you have a full day and drive around the Island from Kailua-Kona south on 11 it is a winding road so if you get car sick easily I would avoid that direction. If not you can stop at a coffee plantation about 7 miles south then go on to mile 104 and turn onto hwy 160 for 3 miles to the state park of point of refuge and walk through that. if you snorkel two step is only a quarter mile east of there with some of the best snorkeling on the Island but no sand in and out on Lava but very easy to get in and out. then there is a drive if you want to go to South point and the green sand beach. You can get rides for 20 dollars ea. well worth it or a brisk walk for 1 1/2 hours each way. We would recommend if this is a must for you maybe do that and go to the Black sand beach and call it a day and go back. Otherwise bypass south point. After the Black sand beach see the sea turtles and go to the Volcano area and see the Lava Tunnels, rain forest, steam vents and Volcano. Depending on the time of day I would go to Hilo stop if you want and on the North west part of town is Rainbow Falls. From there I would head back by saddle ridge road AKA 2000 or Danial K road back to Kona. If you are making good time and left early and dont care about the sunset. From Hilo take 19 North and look at the Cemetery there it is amazing. then just a few miles ahead is a great Scenic view drive. Takes you through a type of rain forest botanical gardens and a path to go down to see where a river meets the ocean where you can walk out and see some great views. After that you will come back to Hwy 19 take a right and then Akaka Falls will be your next turn off about 8 miles in. on the way back there is a small town with a great bakery before you head back on 19. then you start a long drive back. you could stop and see Waiapolo Valley and see the overlook where you are way above it and can see the Black sand Beach there and the North shear Cliffs along with the Valley. You used to be able to drive down the narrow road to the valley drive threw the small river and see the area. Only local owners are allowed to use the road now while it is being worked on which will be a few years in Hawaii. Then back on 19 to Wiamea. from there you can take 19 and continue on or take Hwy 190 back to kona. this would be way to much for the day but gives you an Idea of some spots. Havi was mentioned which is thraight North of Kona about an hour. From there another 30 minutes is another Valley you can walk down to the bottom to the black sand beach and see the cliffs and valley. the steps are lg. and steep it takes 15 minutes to go down and a little longer to get up. The trip around the island is 220 miles I would split it up in a couple days. just a highlight of what to see going around get a map all these and more are highlighted so you can choose what intrests you direction and how far you would like to go. Me I would go to Huggoe's order a dring and look out at the ocean.