If you’re driving to Emerald Bay, one of the lake’s most popular destinations, known for its tiny Fannette Island, the hike down to Vikingsholm Castle is a must. You can take in the view of the bay from the observation area on Highway 89, but most visitors walk down the mountain to the water to see the 1929 mansion and get another perspective on the bay. It’s a wide, out-and-back trail that doesn’t take long, but the change in elevation is almost 500 feet (152 meters), and you do have to hike back up to return to your car. Vikingsholm Castle is open for tours on select days. To continue hiking, join the Rubicon Trail or Eagle Falls trail once you’re on the lakeshore.