Big Island tour. We didn't quite hit the whole island, but we got about as close as you could in a single 14 hour day (!).
Crossing Saddle Road from Kailua Kona side (west) to the Hilo side (east), we stopped for pictures with Manua Kea and its observatories in the background, observed the US Army training howitzer crews, then made it into Hilo and Kaumana Cave and then Rainbow Falls.
Those two relatively minor sights were nice little introductions to just how beautiful the rainy side of the island is, as we headed next to the Thurston lava tube inside Volcanoes National Park. Somewhere along the line we lost the "adults" (Mrs. Tsai, Aunt Sophie, and Vivi) in the other car and ended up just as the "kids" (Sophia, Justin, Alicia, Daniel, Tina, and myself) together.
The steam vents were, well, all that steam from natural rainwater? Sure, when you remember there's two hundred inches of rain per year. The sheer size of the Kilauea volcano's caldera also has to be seen to be believed. You sit at the edge of the outer crater, then look in, and squint, and see that it's merely the edge, with two more craters nested inside. Huge.
The black sand beach (I forget which one we went to) was also impressive. Lines of coconuts sprouting all over the beach, atop piles of black lava rock, some smooth, some sharp, some pounded to round sand of varying sizes. Add in water and it becomes beautiful and shiny. Mackenzie State Park next to watch the waves pound over the cliffs, before heading over to the lava boats to see red, burning lava from the ocean side of Kilauea.
This was perhaps the most incredible part of the trip (ok, the manta rays make it a tie), as you get much closer to active lava off the beach in a boat than you are normally allowed to from land. Vast columns of steam as lava empties into the water in front of and below you, little pops and explosions of lava, and so much heat that the water around you is like a warm bathtub.
Add in sunset on the way back and a few flying fish... what more could you ask for?