The numbers come thick and fast in any trip to Northern Ireland.

We start with the Titanic Belfast, a world-class museum that tells the tumultuous tale of how the "virtually unsinkable" ship was born, built and buried beneath the waves due to a deadly combination of complacency and hubris.

We learn it was built with 3,000,000 rivets, that it took 3000 men at Harland and Wolff on the banks of the River Lagan three years to complete the 52,310-ton vessel. That it had nine decks, 840 staterooms and 10,000 lightbulbs.

They are good, these numbers, as far as they go. They give visitors an idea of the scale of the ship but the next three numbers are why we remember the liner, which embarked on its maiden voyage from Southampton to New York on April 10, 1912, and which hit an iceberg just before midnight four days later and slipped beneath the waves in the North Atlantic Ocean shortly before 2am.

The first number is 2224 - the number of passengers and crew on board.

The second number is 20 - the number of lifeboats the ship carried, only half of what was needed for all the souls on board.

The third number is 1512 - the number of people who perished.

It was a dreadful, shocking loss of life, and one that continues to fascinate people around the world. One that inspires books, movies and plans for multi-million pound recovery expeditions.

The exhibition is set over six floors, with nine interactive galleries. Each floor and each gallery is fascinating. It is a thoughtful, well researched display, which avoids sensationalism, in this most sensational of stories. As I leave the building, the numbers stay with me but so do the individual stories of the men who built her, those who sailed her and those who never reached New York. It is a surprisingly moving experience for a major tourist attraction.

But Belfast has other big numbers, too. Equally dreadful and shocking numbers.

We've been staying at the Belfast Hilton, a modern five-star hotel close to the city centre which offers everything you would expect. Fine dining, a gym, friendly, professional staff and well appointed rooms. The receptionist told me about the city's attractions. He recommended the bus tours so we jumped on the hop-on, hop-off Belfast City Sightseeing tour outside the museum. It does all the usual stuff any tour would do in Glasgow or Edinburgh, or Aberdeen or Inverness. It passes cathedrals, botanic gardens, a university and famous pubs.

It also journeys in the shadow of the so-called Peace Walls - giant metal and concrete partitions, some as high as 10 metres, which split this most divided of cities. It passes Loyalist murals on the Shankhill Road then five minutes later, in what seems like a different world, the King Billy murals are replaced by Republican ones to Bobby Sands and IRA martyrs on the Falls Road. It's a disconcerting experience. The words to Holidays In The Sun by the Sex Pistols come to mind, Johnny Rotten snarling "a cheap holiday in other people's misery".

Our tour guide puts it in context with some more big numbers. Between 1968, when The Troubles began, until 1998 and The Good Friday Agreement, more than 3600 people died, and countless more were injured. The mood on the bus is sombre.

I'm glad the city doesn't try to hide its problems but, still, I'm glad when we leave the flags and emblems, the hate and the seemingly intractable bitterness behind and head back to the city centre, to the bars and the restaurants and the busy shopping centres.

I last visited Belfast more than 20 years ago. The city has been transformed and is a pleasant place to while away the hours, with no sign of any visible tension, apart from a noisy, very colourful Gay Pride demonstration. I can't imagine such a gathering back in the bad old days.

The next morning, I pass a couple of security guards talking in detail about the ramifications of independence for Scotland on Northern Ireland as we head for the ferry. They seem well informed but I don't enter the debate. I'm just glad we have the chance to decide our future peacefully.

It takes less than 15 minutes to drive to the busy port, then we're inside the Stena Ferry and heading for home. As we sail out of Belfast I stand at the stern of the boat and watch as this most fascinating of cities slowly recedes. The impression it's made will last a long time.

Garry Scott was a guest of Stena Line and Visit Belfast. He travelled by Stena Line from Cairnryan to Belfast. A car and four passengers costs £366 return. See Stena Line for details (www.stenaline.co.uk ). Garry stayed at the Belfast Hilton. Rooms cost from £119 B&B.

FIVE OTHER BELFAST ACTIVITIES

1. Ulster Museum

This fascinating museum is the largest in Northern Ireland with over 8000 square metres of exhibits ranging from treasures of the Spanish Armada to displays of botany, zoology and fine art. Current exhibits include Art of the Troubles which runs until September 7. (0845 608 0000, www.nmni.com)

2. Belfast City Sightseeing

The Hop On/Hop Off bus service takes you on a tour of the city's key sights, including Stormont, The Peace Wall and the Waterfront, accompanied by commentary from a local guide. (028 9032 1321, www.belfastcitysightseeing.com)

3. Botanic Gardens

Belfast Botanic Gardens, in the leafy university area of the city, has 28 acres of beautiful grounds. Visit the Palm House - a 170-year-old glasshouse filled with exotic tropical plants - and the Tropical Ravine House with its sunken ravine that runs the length of the building.

4. W5

A big, bright building in the Waterfront area, W5 is an immense adventure and discovery centre which includes a multi-story climbing structure, science demonstrations and endless interactive exhibits. (028 9046 7700, www.w5online.co.uk)

5. Crumlin Road Gaol

A working prison until 1996, Crumlin Road Gaol is a thought-provoking site. Tour groups hear the history of the prison from the days when women and children were detained there, to the more recent years when Republican and Loyalist inmates were segregated. (028 9074 1500, www.crumlinroadgaol.com)