Half Dome hike
17-miles 12-hours with a breath-taking dangerous climb holding chains on the majestic half dome at the end. This hike requires a permit for the final half dome climb.
12-miles 7-hours hike. The trail ends at a point higher than the Half dome. One gets a great view of the park as well as the Half dome from here.
I would recommend doing only one of these two hikes in a single trip.
Scenic viewpoints and Small hikes
The lower falls are easily accessible with a short walk. The upper falls require a 6-mile hike. I only did the former.
Another gorgeous falls accessible with a short 10-minute walk.
Glacier Point provides a great view of the half dome for non-hikers. It is located about an hour away from Yosemite Valley and close to south exit towards Fresno. For hikers, I would recommend doing Sentinel Dome or Taft point; both are one-mile hikes with starting point about 2-miles drive from the Glacier Point.
Mariposa Grove of Giant Sequoias
Mariposa Grove has multiple hikes ranging from short walks to 7-mile hikes where one can see the giant sequoias. Due to time constraints, I only did the short hike here.
Where to stay
If you are doing in the Half Dome, then stay at the Yosemite Valley the previous night to start hiking early morning (4-5 AM). Curry Village has the cheapest lodging, and the camps are located conveniently inside the Yosemite valley. Book well in advance.
The park is huge. Roads wind around mountains and hilly. Driving inside the park can consume significant time, I would recommend planning for that in advance.