Climb or crawl all the way to the top of Halfdome in Yosemite Valley. I've done this trip before compleating the round trip as a young man in less than 12 hours. Now at the age of 62, I'll try it again sometime in May/June. I know it will take longer than 12 hours this time, but my New Year's Resolution is to complete this hike once again, going up to the top and returning to the Valley all in one day!