Wind Mountain is a short, yet steep hike to an excellent view in the Columbia River Gorge that can be done in a couple of hours.
Once you reach the parking lot, walk down the hill and find the trail head, which is easily seen as it is marked. Begin your trek up the trail. The way up is pretty much all uphill, and is a great workout for the legs.
You will walk through forests and over many rocks on the way up. As soon as your legs are burning, you hit the top and see the great views. Walk around on the top and look from both sides. Bring lunch to eat while you are sitting at the top, as the views are magnificent.
After you are done exploring the top, head down the same way you came. This will be hard on the knees in some spots, and if you know you have bad knees, I would recommend trekking poles to help you on your way down.