KALGOORLIE, AUSTRALIA -- His weathered hand clasping a fistful of dollars, Dave Sheehan leans back against the hot tin wall of his roofless gambling den in the middle of the Australian outback. It's a blistering 109 degrees.

"It's never too hot to stop the game," Sheehan says with a wry smile as his son, also Dave, tosses two coins high into the air.

They are playing Two-Up, a game in which gamblers bet on how two old pennies will land after being thrown into the air.

The coins are placed on a piece of wood, one showing the "tail" side and one showing the "head" side, and bets are placed on whether they will both land showing heads or tails.

In Australia, gambling is regarded as a national pastime, but in this mining town in the heart of the western Australian goldfields, it's more akin to religion.

Situated in the middle of a hostile desert environment, Kalgoorlie has always been driven by the lure of instant wealth.

"This place is rotten keen on gambling," said Geoff Brabazon, secretary of the Kalgoorlie-Boulder Racing Club.

"It was founded by gamblers looking for gold and it's never changed."

Sheehan and his four sons, plus a silent partner, run the Kalgoorlie Bush Two-Up School four miles north of the town.

It's an incongruous site -- a large, circular tin shed with its roof cut out, surrounded by a fleet of cars and taxis in the middle of nowhere.

As the temperature soars, Sheehan's eldest son, Bill, rips a sheet of tin from the wall.

Despite its transient appearance, the ring is an institution. It has operated in various locations in and around Kalgoorlie since the late 1800s, when the town was the center of the Australian gold rush.

Two-Up is a serious game in which tens of thousands of dollars can change hands in an afternoon.

While the game has attracted its share of exotic characters -- like Coffin Hat and Big Fred -- it has always been run on a strict code of ethics: no alcohol or children at games, and no games on Good Friday or Christmas Day.

There are also no games on pay day, Sheehan said. "We gotta let them take their money home to their wives."