There are many fantastic overlooks along East Tennessee's Foothills Parkway in Great Smoky Mountain National Park. The best is Look Rock because of the option to take a short hike up to an observation tower, earning 360-degree views of the foothills and the tallest of the mountains.
Park in the large, signed lot just off the parkway. At one end of the lot is a stone platform that overlooks Happy Valley and the hills surrounding Cades Cove. This is worth a quick look, but the real treat takes a little more work. Cross the parkway on the pedestrian path just uphill from the parking lot and take the half-mile paved trail to the top of the ridge. Soon the tower will come into view. This large structure is used as an air quality and weather monitoring station by the National Park Service and a viewing deck for the public. An ADA-accessible (but steep!) ramp leads to the top, and all of a sudden you are peering over the tree tops to the valleys below.
On a clear day you can see for miles in all directions. Immediately beneath to the south is Happy Valley, and the hills beyond that hide Abrams Creek and many acres of rugged, roadless foothills. To the east lies Cades Cove tucked behind hills of green. The prominent ridgeline beyond is the spine of the Smokys, which is also the path of the Appalachian Trail and the Tennessee-North Carolina border. High points are Gregory Bald far to the right (south), and Thunderhead Mountain to the left (east). Beyond that, Clingman's Dome rises in the distance, and even further away, due east, is Mount LeConte. Looking northward grants a great view of Maryville, with Knoxville and Oak Ridge further away. If you can make out mountains on the distant northwest horizon, you are seeing all the way to Frozen Head State Park and the rest of the Cumberland Mountains.
The Smokies get their name from the natural fog that frequently blankets the valleys and from a certain amount of natural haze in this humid climate. Air pollution has unfortunately made East Tennessee's visibility far worse, however, so a clear view from Look Rook is very rare and nearly impossible in the summer. Come early in the morning for the least hazy conditions or at night for some of the best stargazing in East Tennessee.
The best time to visit is fall when the leaves are changing and the crisp air has begun to clear up. Winter brings the best visibility and potential for snowy vistas, but use caution driving Foothills Parkway because the road can be treacherous even if it is not closed for winter weather.