Destination: Edinburgh Tour; Age appeal: Not young children; When to go: Anytime.

Hidden deep beneath Edinburgh's Royal Mile lies one of the city's best-kept secrets a warren of streets which offer a unique insight into how long-forgotten lives were lived and lost.

The Real Mary King's Close is a popular attraction which allows visitors to travel back in time more than 300 years. Consisting of a number of streets, known in Scotland as "closes", the attraction features a series of almost perfectly- preserved buildings dating back to the 16th century which stretch up to seven storeys high.

In 1753, the city's council decided to develop a new building on the site. The houses at the top of the close were kept or used as foundations. But the lower sections were left beneath the new building, dark and ancient dwellings steeped in mystery.

Ever since, Mary King's Close, named after one of its best-known inhabitants, has remained a magnet for historians, academics and even ghost-hunters searching for the spirits some people claim to have seen at the underground site.

Since April 2003, guided parties of visitors have been able to visit The Real Mary King's Close itself, and other Closes and spaces which lie hidden deep beneath Edinburgh's City Chambers some of which have never been open to the public.

Stepping down into the site was a fascinating experience. A dark staircase weaves its way down through centuries of rock and stone and emerges directly into Mary King's Close, a 10ft wide alley-way stretching more than 50 metres into the dimly-lit distance.

At various points off the alleyway doorways lead into a series of dark and eery dwellings which look like their inhabitants left yesterday.

It is impossible not to sense the atmosphere of the site and feel the shadows of street children, merchants and housewives brushing past.

Our tour included a look at the simple home of a grave-digger's family stricken by the plaque which hit Edinburgh between 1644 and 1646, and a stop-off at a shrine dedicated to Annie, a young victim of the epidemic.

A Japanese psychic claimed to have discovered Annie's ghost while visiting Mary King's Close in 1992. She told staff she had felt a presence when she had entered a small room off part of the underground alleys beneath the Royal Mile known as Allan's Close.

After communicating with the spirit she discovered she was a young girl heartbroken after losing her doll. The psychic put a doll into the room to comfort her and sensed she was delighted. Ever since, visitors have left hundreds of toys and gifts for the young girl.

Mary King's Close has fascinated historians for centuries. Now it is open to all, the attraction is certainly one of Edinburgh's finest and well-worth a visit whatever your views on the after-life.

After all the excitement of the tour, I headed back to the Apex City Hotel which is located in the Grassmarket in the heart of Edinburgh's Old Town with stunning views of the castle.

All of their 119 rooms contain a wide-screen TV, DVD and CD player and a walk-in bathroom with power shower. Guests can also make use of all the spa facilities which include an ozone pool, tropicarium and gym or enjoy a romantic meal for two in the relaxing Agua Restaurant.

On its doorstep are all the prime shopping and entertainment attractions which bring in tourists from around the globe, including the Royal Mile, Princes Street and Holyrood House.

l Tomorrow, the attraction is offering visitors the chance to join five of the UK's top psychics on a late night tour of the historic site to catalogue the number of spirits they communicate with. Tickets are priced at £12. Call 08702 430160 to book.