For our first adventure on the Big Island, we headed from our flight in Hilo to Hawaii Volcanoes National Park. Lots of people venture here to see hot molten lava flowing. We did too, but that lava flows here are unpredictable, so that wasn't in the cards for us. We did explore the park anyway though by driving and hiking the Chain of Craters Road and Crater Rim Drive.
Crater Rim Drive is a nice loop around the summit of the caldera, but I personally liked the Chain of Craters Road better. This will take you down to the ocean, where you can see the lava that hit the sea. You'll pass by lava flows from different years. It's pretty humbling to see the power of nature here. There's a spot where lava flowed over the road, but we didn't make it on a hike there, as the wind was blowing pretty hard. Instead, we ventured to the Sea Arch, which formed when lava flowed into the sea. The waves crashed against the cliffs and through the sea arch, forming rainbows in certain points as the sun shone through the spray.