Having a husband who does things like this for fun makes it easier for our kids to know that hobbies and projects are the stuff of a happy, real life. The boards are the front frame of a "Viking A-frame" tent. More information will always be discovered, but in those places and times, there were some stone walls that seemed designed to have one of these put on top of it (like RV camps, the stone walls stayed, but those spending the night there put up their own roofs) and I've read that such tents were also set up on the decks of ships, for sleeping during rain. The ship's sail could be used for a tent.
There's another kind of tent that can be made from a sail and two oars. We've done those (with two poles and a long piece of cloth), but I don't know if there are photos.
Those front boards were carved into dragon heads, using knots in the wood for eyes. They're really beautiful close-up. Here's the front and back of those:
You can click those for a closeup, and click that one again for a REALLY close look.
That blue background on the top image was not Photoshopped in. That was the sky from our front yard yesterday.
More of Keith's knotwork and carving, and some of Holly's early knotwork, are here: SandraDodd.com/knotwork
The more curiosity and exploration and creation you have at your house, the more effortlessly learning will flow.