The park itself is rather modest, with a swing set, tennis court, grassy area, and a couple of small covered picnic areas. It's the Bighorn Sheep, however, that make this park worth visiting. If your timing is lucky, you'll see a large herd of sheep right there on the park grounds. It's great for a photo op, and they aren't as shy as you might expect. It's also not unusual to see sheep roaming around the nearby neighborhood, even congregating in residents' front yards.
Unfortunately, you never know when you'll see the sheep, and it could take several visits in order to catch the sheep while they're out. I've found that mornings and early afternoons are the best time to see them.
Perhaps the other feature which makes this park unique is its panoramic view of Lake Mead. Thus, between the sheep and the view, there are plenty of photo opportunities to be found here. As a park for play and activities, Hemenway is not exceptional.
There is a small parking lot, which can feel a bit tight if more than a few cars are there. Street parking, however, is ample.