Okey Dokey boys, let the lady tell ya about the heart...
It was placed there as part of the tourist draw. The legend says that any woman of marrying age who chooses to walk over the heart will be wed within one year.
Personally, every time I've been to Howe Caverns I've never walked on the thing. And you should see some of the guys do everything they can to avoid even going near it. ROFL
Ask any guide, it's one of their favorite parts of the tour. Watching people do anything to avoid the heart at all costs or watching girls try to drag their boyfriends across the thing.
If something happens where the power fails and an emergency develops during a tour guides are taught a route where people can get out of the cave by wading through the freezing cold water, past the end point of the boat tour, and climbing over and around some natural areas which lead to the mouth of the cave. Where someone with a key to the gate would be waiting, hopefully, to let everyone out. All in the pitch black by the way - hey the power has gone out, remember.
From the Howe Cavern website - "The plans include putting the entire cave system back together as one system as it was when the cave’s discoverer, Lester Howe, began giving tours of the natural attraction in 1842.
“The goal,” Mr. Holt said, “is to expand past the experience beyond the popular boat ride on the underground Lake of Venus and to open more than 1,800 feet of undeveloped cave. Many parts of that end of the cave, which was the natural entrance used by Lester Howe, haven’t been seen by the public in more than a century,” he noted.
That sounds like the area beyond where the boat tour ends and perhaps the areas they take you to for the "adventure tour". Which is their spelunking tour. The natural end of the cave is where the elevators are that take you to and from the visitor center, up above.
I've been to Luray Caverns and Howe Caverns and caves all over the place. Must say Howe Cavern's lantern light tour wins for best small cave tour. They turn out all the lights in the cave and you have only your little lantern light. You get a fresh perspective and can imagine what it was like for the adventurers at the mid 19th and turn of the century who came to visit the cave before modern electricity burrowed down and lit the stalagmites and their friends.
Your lantern consists of a candle in a small paint can. Really simple and really effective since the can is on it's side with one end open. Absolute low tech, no tech and an amazing way to experience the cavern.
As for treasure hunting the cave...don't bother. It's well maintained and any foreign objects are removed so the environment of the cave and formations won't be damaged. There is the little "wishing well" with the money going to charity but the rocks there are monitored for contamination from the coins and the coins are regularly exhumed, cleaned, counted, and sent on their way to help people in need via the charities.
Luray caverns is certainly bigger and better known than Howe caverns but Howe has a charm all it's own.
If you get the chance, go and take the candlelight tour. Let your mind wander and wonder.