To solve the Mystery Spot 47 puzzle you had to figure out what named place in which of America’s 397 national parks can be identified by interpreting the following clues:

Along the shore there are seekers of ore
In an ancient keep, high above a vast deep.
My mind’s eye saw them
Though they’re not real men
As we passed them once, and soon once again.

Bonus clue, no extra charge: Some are round and hollow, their glitter hidden.

The answer is Miners Castle in Michigan’s Pictured Rocks National Lakeshore.

Pictured Rocks National Lakeshore is situated along a 42-mile stretch of Lake Superior’s south shoreline in Michigan’s Upper Peninsula. While it does not extend very far inland, just five miles at its maximum width, the park contains a treasure trove of scenic and recreational delights, including multicolored sandstone cliffs, beaches, sand dunes, woods, seven named waterfalls, inland lakes, and watchable wildlife.

The vast, amazingly deep inland sea that is Lake Superior offers panoramic views to distant horizons. The shoreline views at Pictured Rocks are gorgeous too, and the most popular scenic overlook is Miners Castle, a distinctively-shaped rock formation perched high atop a shoreline cliff. Motorists can reach Miners Castle via a spur road, but visitors can also view the rock formation during shoreline cruises aboard tour boats operating out of the western gateway town of Munising.

Here is how the clues lead you to the answer:

Miners are seekers of ore.

A Medieval castle had a keep inside it. Commonly built in the form of a tower, the keep was heavily fortified and meant to serve as a refuge if the castle's outer walls were breached.

If you have seen something in your “mind’s eye,” you have pictured it.

Rounded rocks called geodes are hollow inside, and their inner surface is lined with glittering crystals (commonly quartz) that are hidden from view until the geodes are split or sawed open.

Pictured Rocks tour boat passengers view Miners Castle “once and soon once again” because they pass it twice, seeing it to starboard on the outbound leg of the shoreline cruise and to port as the boat returns to Munising.

Congratulations to the eight Traveler readers who figured this one out: jchappell740, Ranger Dave, Eric Nelson, David Crowl, KevinM, Ken, sierra Sharon, and Eric. All have qualified for our monthly prize drawing and a chance to win a signed copy of Stephen R. Brown's beautiful photo book, the Jewel of the Mall: The World War II Memorial.