By Allison Jones, The Canadian Press

HAMILTON, Ont. - The whereabouts of a coral necklace that adorned the neck of the Duchess of Cornwall's great-great grandmother, and is said to ward off evil spirits, aren't known, but the royal couple are sure of one thing.

It's "not with us," Camilla said with a smile Thursday as she and Prince Charles toured Dundurn Castle.

The castle was home to Sir Allan Napier MacNab, Canada's pre-Confederation prime minister from 1854 to 1856 and the duchess's great-great-great grandfather.

As the royals toured the opulent home in this southern Ontario city, they first stopped at a portrait of MacNab. Their gaze then turned to a painting of his daughter, Sophia, shown wearing the jewelry in question.

Curator Ken Heaman gave the couple a short briefing on the necklace's rumoured ability to keep evil at bay, adding he wished he knew where it was now - the musing that led to Camilla's comment, which also brought a grin to the lips of the prince.

The castle visit was part of the royal couple's 11-day Canadian tour, their first visit as a married couple.

Outside, an excited crowd numbering in the hundreds greeted the royals and Charles went out to meet the emotional onlookers, shaking hands with many of them.

"My mother would be here if she could. I'm here," said 81-year-old Helen Coverdale, tears filling her eyes.

Coverdale, whose mother is from Britain, said "It's heritage. It's what I'm proud of."

"I choose to be a royalist," she said, adding she got up early in the morning to watch both the Queen's wedding and Charles' first marriage, to Diana.

"We'll do the same for William when he gets around to it."

Trish Pond, with Ashley Laidlaw, 5, and Olivia Laidlaw, 3, said she "came out for the experience for the girls to get a glimpse of Prince Charles and the Duchess of Cornwall."

"They're excited. They're all into princesses and that sort of thing."

The royal couple also drew a large crowd when they visited HMCS Haida, a national historic site, and took turns firing four-inch guns on the top deck of the ship known as the "fightingest ship in the Royal Canadian Navy."

Camilla put her hands over her ears to brace for the sound, so Charles went first. He assured his wife that "it's only a small one."

While the prince's gun wasn't very loud, Camilla pulled the trigger on the second, which was quite a bit louder, and she laughed.

The prince then traded munitions for a wine glass as he toured the Niagara College Teaching Winery.

Charles walked in gingerly from the wet outdoors to the visitor and education centre and joked that he'd already been into the good stuff.

"We've been drinking wine already," he quipped before sampling three teaching winery wines: a Chardonnay, a Meritage and a Cabernet Franc icewine.

The process of making icewine, a speciality of the region, was explained, namely how the grapes are harvested when the temperature has been at -8 C for three consecutive nights. He seemed particularly interested in the icewine and called the process "fascinating."

Although Charles' belly was presumably full not only with wine but also with cheeses made by students from the college's Niagara Culinary Institute, he did not leave empty-handed.

At a reception where the prince unveiled a commemorative plaque for the centre, Ontario Transportation Minister Jim Bradley said Charles would receive a gift of the wine he sampled.

Charles and Camilla began their Canadian trip Wednesday in Newfoundland and will make several stops in Ontario, British Columbia and Montreal before ending their tour Nov. 12 in Ottawa.

Camilla's trip to Dundurn Castle allowed the duchess to reconnect with her Canadian roots, and she asked numerous questions about the house and its history.

Tom Minnes, the curatorial assistant at Dundurn, says the duchess's great-great-great grandfather was an early nation builder, sowing the seeds of Confederation through railways.

MacNab also helped suppress the Upper Canada Rebellion of 1837, for which he was knighted in 1838 by Queen Victoria.

MacNab's family came to Canada from Scotland and he was born in Niagara-On-The-Lake, Ont., in 1798.

Minnes says he is also notably referred to as the "boy hero of the War of 1812," having served at the age of 14.

The royal couple were to return to Toronto where Charles was to present new colours to the Royal Regiment of Canada and the Toronto Scottish Regiment.