Of all the hiking possibilities in and out of Yosemite Valley (arguably) Half Dome is the most exciting. I know of no other trail in Yosemite, that has the combination of such beautiful land and water scenery, incredible trail engineering and yes, the adventure of a 400 foot vertical gain on a 45 degree slope up smooth granite via a cable ladder.
All the above makes Half Dome a "must do hike" for all those who are willing (and capable of) putting in the necessary hard work to gain its 8,800 foot summit.
Your hike up Half Dome starts at shuttle stop #16 in an area known as "Happy Isles" located in the eastern end of Yosemite Valley.
But before we get started, there are a few things you need to think about. First, how about your physical condition? The Yosemite Visitors Guide describes the Half Dome hike as the most strenuous day hike in all of Yosemite. You will be traveling on foot anywhere between 14 to 16.3 miles round trip (depending on which trail you take), and gaining nearly 4,800 feet of elevation. Needless to say, it is a serious hike. Most folks who are successful in making the summit take between 10 to 12 hours to complete the it, so you will need to set a day aside to make your attempt. Next, is whether you are subject to Altitude Sickness
at moderate elevations. If so, you will need to take a bit more time to acclimate.
If the above seems a bit intimidating, or if you have younger folks along, there is the option of backpacking up to "Little Yosemite
Valley," camping there, and then completing your summit bid on Half Dome in the morning. This splits up the hike into about two
equal parts. This approach would make things a lot easier if you are not quite up to a single push to the summit. If you adopt this
method of attack you will need a wilderness permit for an overnight stay in Little Yosemite Valley. You will also need to protect your
food (and ultimately the bears) by carrying a bear box (required), because bears certainly frequent this area of Yosemite.