The hike up Fronalpstock and Klingenstock (aka Chlingenstock) offers amazing 360-degree views of the Mythen, Lake Lucerne, and the surrounding mountains. The hike begins and ends at the bus station in Morschach, Schwyzerhöhe. However, you can modify the hike easily to begin or end at the Brunnen train station or the Stoos mountain station. The round trip starting and ending at Schwyzerhöhe is about 20 kilometers (12.4 miles). Starting or ending at Brunnen instead adds about 4.8 kilometers (3 miles) each way, but you can easily take the bus to Schwyzerhöhe. You can also begin the hike at Stoos instead. You'll need to take the bus from Brunnen to Morschach, Luftseilbahn (the end station), and then take the cable car up to Stoos. This saves about 3.8 kilometers (2.4 miles) each way.
The path begins at Schwyzerhöhe on a paved road that leads past a few farmhouses. Follow the signs to Stoos. The road turns into a gravel road. Also, be warned - the road is used for cattle, and there can be a lot of manure and flies. Fortunately, you also get some nice views of the Mythen on the way.
After about 2.6 kilometers (1.6 miles) there is a sign to the right marked "Fronalpstock," which is an alternate path up the mountain. Otherwise, just stay on the road to Stoos.
At 3.4 kilometers (2.1 miles) you will reach Stoos. Turn right toward Fronalpstock at the sign. You will pass a few hotels and the cable car station. Shortly after this, at 3.8 kilometers (2.4 miles), turn sharp right and follow the sign on the trail toward Fronalpstock. The trail continues up the hill, curving to the left and following a few switchbacks before passing the Bergrestaurant Welesch, then another cable car station. The trail continues up toward Charenstöckli, offering great views of the Mythen as well as the ridge between Fronalpstock and Klingenstock. Huser Stock is visible to the south.
At 5.8 kilometers (3.6 miles), the trail splits; take the right hand path. (The left path also eventually leads to the summit of Fronalpstock, but the right-hand path offers better views.) The path does not actually lead to the summit of Charenstöckli, but the summit will be close on your left. At this point, continue following the yellow trail signs toward Fronalpstock. Soon the summit restaurant and cable car at about 7.5 kilometers (4.7 miles) will come into view. There are several platforms for viewing the Vierwaldstättersee (Lake Lucerne) below. The summit can be busy because of the cable car, but continue along the ridge and the crowds quickly thin out.
Head south along the summit. There are two trails; take either one, since they merge shortly after. Both will be marked by white-red-white blazes, meaning "mountain path." At around 8.5 kilometers (5.3 miles) you will come to a small hut with an intersection. Follow the signs down the switchbacking trail toward Furggelen and Huser Stock. At 9 kilometers (5.6 miles) you will reach Furggelen, which is just another small hut. You have the option to turn left here and head down to Stoos to end the hike early.
Continuing toward Huser Stock and Klingenstock is simple; there is only one trail along the ridge (a few trails diverge to the left back to Stoos), so follow the signs to Klingenstock. The trail becomes more narrow along the ridge, including a few spots where chains are used. However, the trail is very well maintained, and there are numerous stone and wooden steps along the trail.
At around 9.5 kilometers (5.9 miles) the trail to Huser Stock leaves to the northwest. The summit is less than 10 minutes away at this point, and the trail is an out-and-back. There are two more nearby trails leaving to the north back to Stoos, in case of bad weather or if you need to shorten the hike. After Huser Stock, continue along the ridge toward Klingenstock. There is another cable car station here, and the views are incredible.
From Klingenstock, continue down the trail in the same direction (approximately east), then turn left (north) to head down the trail toward Stoos. The trail is a bit hard to follow in some spots, but basically the trail just continues down the hill toward the village. At around 13.7 kilometers (8.5 miles), you will reach a road. Turn left (west) toward Stoos, and follow the road back to the village. You'll have to turn right around 14.3 kilometers (8.9 miles), but just follow the yellow signs again.
Once in Stoos, you can take the cable car back to Morschach or walk down the same road you came up on. It's about 3.8 kilometers (2.4 miles) back to the bus stop at Schwyzerhöhe from Stoos.
To sum up, the hike up Fronalpstock and Klingenstock is an absolutely epic hike with amazing views of the lake and the surrounding mountains. The trails are all well-marked and safe. There are lots of options for distance, depending on how strenuous you want the hike to be and how much time you have. For more information and maps, the SwitzerlandMobility app and their website are highly recommended. So get out there and enjoy the hike!