If you like sweeping vistas, wildflowers, and (ahem) squirrels, this is a hike you should consider. At eleven miles, its relatively lengthy, but starting at Twin Gates eliminates some of the elevation gain and makes it a little easier in that regard.
The Canada de Pala trail goes up from the parking lot, past the upper end of the Yerba Buena trail and crests at a place with a large fallen oak; a very nice place to stop and take in the view (see my Oct 31 hike). A tall remnant of the long dead tree juts like a tooth at the crest of the hill. On a clear day you can see the bay as far north as the Dunbarton, and even on a foggy day the observatory looms above you from the peak of Mount Hamilton to the Southeast.
The trail then dips down and crests again, just a little higher before it drops down and passes the upper ends of the Los Huecos and Halls Valley trails. In the springtime this trail is littered with a fantastic variety of flowers, but even in the winter, with a brisk wind clearing out the smog at the southern end of the San Francisco Bay, the views are awesome.
Antler Point, is at the end of a .3 mile single track that cuts off of the main trail. The view is fantastic on a clear day down in the bay area.
There’s another beautiful overlook up there but it looks down into the Smith Creek canyon. I recommend you take a look if you go up there as the hillside is very steep there as it drops some 1500 feet into the canyon.
The park can get very hot in the summer. You are way out in the boonies in this hike so it's possible to encounter any kind of the indigenous wildlife you may have heard of, save Bigfoot. No Bigfoot, they're afraid of the observatory.