The trip up Haleakala is a climb from near sea level, up above the clouds, and then down into another world entirely. All within 25-30 miles.
You start out at the bottom with normal traffic, road signs and what could be anywhere else. But if you look forward, you see something climbing up into the clouds. It appears massive.
You go along normal fences, simple wild flowers along the road, and even glimpse off in the distance another volcano rising up. Presently you turn off onto the main road to the top, rising up into and then breaking through the clouds.
Along the way you might see a cross with flowers on it where someone had lost their life on the road, or large stones scattered over orange colored ground. The plant life becomes different somehow - it looks like it really has to struggle to grow in this rough terrain.
Suddenly you break out above the clouds. Looking out and down you see a sea of white water vapor. Peaks stick out here and there. And above you can see cars still climbing up through a mist even higher.
At the top, you are literally on top of the world. The sun is shining bright, the landscape is rough and seemingly barren. You see interesting individual plants tucked away and if lucky will see a few Hawaiian geese wandered across the hard ground.
Further on up the road you see astronomical observatories. But if you allow yourself a chance to walk, you follow the Sliding Sands trail over the ridge and into another world entirely. If it weren't for the occasional plants or the clouds sneaking up in patches from below, you could believe that you had somehow ended up wondering on Mars or some other distant planet.