The Welch Mountain and Dickey Mountain Loop equals two mountain summits one one loop in the White Mountains range! It's the perfect day hike 2 hours from Boston.
This is a very well-marked and traveled trail, marked with yellow blazes. Start off at the trailhead (easy parking, $3 fee) and be sure to go counter-clockwise for the best route. The beginning of the trail meanders along next to a babbling brook and through forested terrain. The climb gets steadily steeper - once you're above the treeline, the rock scrambling begins.
After about 1.3 miles you reach extensive views on the open ledges of southern Welch mountain. Once you reach the summit of Welch mountain, enjoy the 360 degree views and grab a bite to eat. Continue following the trail and descend down the opposite side of the Welch mountain peak. You'll have to do more uphill climbing to get to the peak of Dickey, but it's well worth it.
The descent is roughly 2.1 miles down, very manageable. Take caution with the uphill rock scrambling - some parts can be very steep. I recommend caution particularly with rain or slippery conditions.
Pro tip: After the hike, stop off on Upper Mad River Road and soak your feet and cool off in the Mad River. It's amazing in the summer :) Ice cream shop just down the road near Thornton is also awesome!