The first thing that becomes apparent once inside the Leprechaun Museum is that the venture is misnamed. This is really a folklore museum, and all the better for it. In fact, the museum, located across the road from the back entrance of Jervis Street shopping centre in Dublin, is attempting to take back the little guy from Twee land.

For decades now, leprechauns have been associated with a hackneyed image of the old sod, usually propagated from some cheap film lot on the west coast of the USA. Back here, we run a mile from them, as if they were carrying a virus to be avoided at all costs.

Tom O'Rahilly has no such issues. He happened upon the idea for a leprechaun museum in 2003. He had a long interest in mythology and he saw a gap in the market.

"The idea just came to me," he says. "Initially I didn't think it would work. Even getting a premises would have been difficult. The property market was running away. And at the time the country mightn't have been ready for something like this."

In the foyer of the museum, a mounted case houses the first written record of the sighting of leprechauns. The script dates from the 8th century, although lep stories were passed down orally for centuries before that.

Inside, the visitor first goes through a tunnel that operates optical illusions to considerable effect. This facilitates passage into the world of folklore and fairies. There follows a series of rooms. The first is a reproduction of the Giant's Causeway, which is rich with folklore, and includes the mention of a giant, who, presumably was the alter ego of the leprechaun.

Next there is a giant's room, in which table, chairs and a dresser are three times the normal size. This corresponds to the size difference between a leprechaun and an adult. If, of course, you believe, and why wouldn't you?

There is also a rain room that leads to the rainbow room – can't have one without the other – where the crock of gold awaits.

Elsewhere, the facility has a giant map that illuminates all the folklore centres such as stone forts and the like around the country.

The "experience" as, marketing manager Ciara Gogarty describes it, is "text light". "You don't have to queue up going through the rooms waiting for people to read," she says. But you can learn all you need to know about leprechauns, fairies and folklore in the restaurant, which is located somewhere over the rainbow.

Did you know, for instance, that the habit of spitting on your hand before shaking on a deal originated in a fear that you might be dealing with a fairy? Apparently, the fairies suffered from some class of obsessive compulsive disorder that ensured they would never get into contact with dirt, or spittle for that matter. So there you go now, all you fairies out there.

There is much in the experience to commend and anybody who has the bravery to start up such an esoteric venture in the depths of the recession deserves support.