Edinburgh is a gem, and all the more valuable for being within easy reach. You can eat breakfast at home, take a quick trip up the East Coast mainline and reach Scotland's capital city with time to unpack before lunch. And once there, there is much to treasure.

During a 48-hour stay, I visited the stunning castle - a UK top ten attraction - the Royal Botanic Garden, the Royal Yacht Britannia at Leith and the Museum of Flight at East Fortune, where one of British Airways' fleet of seven Concordes is the proud centre of attention.

I also spent several hours underground in the twilight world of the alleyways and wynds - or closes as they are called in Edinburgh. These closes are cut into the cliff sides. They spill like streams from either side of majestic Royal Mile that forms the backbone of the Old Town, from the castle at the top down to the Queen's official residence in Scotland, the Palace of Holyroodhouse.

Some of these alleyways are still used today, enchanting windows on a past world; others bear more gruesome witness to the lives of medieval city dwellers. The wealthier of these - merchants and craftsmen - lived closest to the top, the poorer souls forced deeper into the bowels of the earth.

When they were first hewn from the volcanic rock, these closes had the benefit of fresh air and daylight, albeit from high above. But the city literally grew over their heads, each new building entombing the homes of people who lived below. Now their ghosts haunt the vaults and make a splendid - if occasionally unnerving - diversion for tourists.

Suitably costumed guides in Mary King's Close take visitors through an hour of quite 'orrible history, from murder to the black plague.

Another tour group offers 90 minutes of night-time drama, packed with detail about the subterranean tragedies and triumphs - and the perennial problem of what to do with your waste products. (They all ended up in the vile Nor' Loch at the foot of the cliff, now the prized - and well-fertilised - Princes Street Gardens).

For visitors interested in the paranormal, or the plain macabre, Edinburgh has a seemingly endless menu. A tour guide following the footsteps of author Ian Rankin's Inspector Rebus delights in encompassing the seedier side of what the writer describes as a schizophrenic city, including the murderous goings-on of Burke and Hare, purveyors of bodies to the nearby Royal College of Surgeons.

Back on the bright side of life, but still in the Old Town, I stayed at the Radisson SAS. It's the only hotel actually on the historic Royal Mile. Its 16th century style facade hides four-star luxury behind walls that have just witnessed a £5m transformation. The only spirits here are those that warm the soul. The hotel's new Itchycoo Bar provides distinctive mix-and-match starter-size meals, using fresh local food. Diners in Durham City can look forward to a treat if the Radisson being built on the riverside there offers the same.

A short trip to Edinburgh demands sacrifices. With the exception of diving into Royal Mile Whiskies to buy a bottle from the 1,000 malts and bourbons on stock, shopping was off the list. The classical 'New Town' with its impressive Georgian grandeur was but a short walk away, but the designer decadence of Harvey Nichols, opened in 2002, and the shrine to shopping that is Jenners - the oldest department store in the UK - will have to wait until next time.

The Museum of Flight, East Fortune

The museum is on a protected First and Second World War airfield and steeped in aviation history. In 1919 the R34 Airship took off from the airfield on its record-breaking first east-west transAtlantic flight, but it has been the arrival of supersonic Concorde that has seen visitor numbers soar.

In 1976, Concorde G-BOAA was the first of the British Airways fleet to fly commercially. After the Paris crash of July 2000, when all 113 on board an Air France flight perished, she returned to Heathrow and never flew again. Her story, including news coverage of her epic voyage by land and sea to the museum, is told through the eyes of the pilots, flight engineer, cabin crew and passengers in a 12-minute film as part of the Concorde Experience exhibition.

Visitors taking pre-booked audio tours on board can follow in the footsteps of the rich and famous as they recall their thrill at flying at twice the speed of sound on the edge of space. The journey time to London from New York was two hours and 53 minutes.

The Concorde dream, from drawing board to demise, is all there, but the museum has much more. Friendly staff show exhibits from the world of civil and military aviation, from the dawn of flight to the RAF's first supersonic fighter, the English Electric Lightning. It's a great place for a day out with lots of hands-on fun for children.

* Admission, including The Concorde Experience, is £5 and £4, with children under 12 free. A Concorde boarding pass with personal audio is an extra £3 and £2, booking essential on 0870 421 4299.

Museum of Flight, East Fortune Airfield, East Lothian EH39 5LF. (01620) 880308.

Edinburgh Castle

Truly a five-star castle, now part of Edinburgh's World Heritage site. The displays are superbly done. The Honours of the Kingdom exhibition tells the story of Scotland's Crown Jewels - saved from Cromwell to become some of the oldest surviving regalia in Europe. Alongside is the famous Stone of Destiny - taken to Westminster Abbey in 1296 and returned to Scotland 700 years later. The new Prisoners of War exhibition tells the stories of sailors from many countries held captive in the vaults in the 18th and 19th centuries. Reasonable wheelchair access (steep!).

* Open all year, seven days a week. Times vary. Closed Christmas Day and Boxing Day. Admission: adults £9.80, children £3.50, concessions £7.50. (0131) 2259846.

The Royal Yacht Britannia, Leith

It took three hours to set the 56 places for a state banquet as Britannia's dining room staff meticulously measured the position of every knife, fork and spoon with a rule. That is one of the many nuggets gleaned from your personal audio as you step aboard Britannia and see the yacht from the engine rooms, though the crew quarters to the bedroom where Prince Charles, Princess Anne, Prince Andrew and Princess Margaret all honeymooned. The yacht, decommissioned in 1997, sailed more than a million miles over 44 years.

* Open daily except Christmas Day and New Year's Day. Times vary. Wheelchair accessible. Admission: adults £9, senior citizen £7, child (5-17) £5, under fives free, family (2 adults and up to 3 children) £25, student £5, Armed forces £7. (0131) 5555566.

The Royal Botanic Garden, Edinburgh

Just a mile from the city centre, the garden offers an oasis of botanical wonders, from a Chinese hillside to a Scottish heather garden. There are also the famous glasshouses featuring Britain's tallest palm house and plants from around the world growing in ten climate zones.

Most areas are wheelchair accessible.

* Entry to the garden is free. Glasshouses admission is £3.50 adults, £3 concessions, £1 child and £8 family, 50p for audio guide.

Guided tours cost £4 (£3.50 concessions) and leave from the West Gate at 11am and 2pm daily from April and September. Booked tours available year round. (0131) 2482974.

TRAVELFACTS

* GNER runs fast and frequent services from the North-East to Edinburgh. Return fares start from £18.50 from Darlington. To book, visit www. gner.co.uk, call Telesales on 08457 225 225 or visit any staffed National Rail station.

* The Radisson's midweek rate is £110 per room per night; weekend B&B rate is £130 per room per night.

Contact the Radisson SAS Hotel, 80 High Street, Edinburgh EH1 1TH www.radissonsas.com (0131) 5579797.

B&B can be found on the Royal Mile from about £25 per person.