See the port before it gets the theme park treatment

TRAILS OF THE UNEXPECTED Andrew John Davies takes a walk around Old Portsmouth, soon to be given a glitzy make-over

In 1758, General Wolfe wrote scathingly of the "diabolical citizens of Portsmouth". He went on: "It is a doubt to me if there is such another collection of demons upon the whole earth."

These demons would certainly be surprised by current plans to transform the city. The recipient of largesse from both Lottery and government funds, Portsmouth Harbour will be turned into a Disneyesque extravaganza complete with hi-tech fountains, observation towers and massive water arches.

Personally, I love Old Portsmouth the way it is, particularly its pubs full of Jolly Jack Tar types with brawny forearms and hearty laughs. Here is the city which for centuries has kept an eye on those dastardly French across the Channel. Any fancy stuff is regarded with a distinctly jaundiced eye.

The worst thing about Portsmouth - the only British city perched on an island - is actually arriving there. By car, concrete tower blocks and the hideous Tricorn Centre offer a heartless welcome; by train, acres of scrubland and the football ground at Fratton Park are dingy if atmospheric. But persevere. For a start, Portsmouth and Southsea station is a Victorian delight boasting some fine ironwork, while a stone's throw away stands the imposing Guildhall, reminiscent of the great Northern town halls.

Walk down towards the florid Edwardian extravaganza of the Municipal College, now the University, and then enter the delightful Victoria Park past one of the country's finest war memorials which is guarded by two menacing machine-gunners. The Park contains a charming aviary as well as an unusual collection of memorials recalling imperial mishaps and triumphs. To the right is the attractive glass edifice of Zurich House with the crenellated headquarters of the Territorial Army tucked behind. Leave the park by the entrance in Edinburgh Road facing the Catholic Cathedral.

Portsmouth is crammed with so many good things that the walker now faces a difficult decision. Dedicated enthusiasts will happily surge up Alfred Road towards the red-brick late Victorian church of St Agatha's with its exquisite interior, ignore the Tricon and then visit the place where Charles Dickens was born in February 1812. This cobbled backwater has hardly changed since the days when his father, John, the original Mr Micawber, optimistically hoped something would turn up.

However, to go back to the Cathedral, turn left down Queen Street past assorted garrison buildings. You are heading for the Victory Gate and yet another dilemma. Through the gate is the 300-acre dockyard and naval base, which boasts a magnificent collection of historic ships and exhibits. Even the most dedicated landlubber can't help but be impressed by the sight of Nelson's Victory, the Mary Rose and, for my money, the star exhibit, the ironclad battleship Warrior, whose lofty masts still catch the breath. Don't, however, overlook the beautiful but functional storehouses, particularly the Double Ropehouse of 1776. Yet this is another walk in its own right.

Instead, turn left down The Hard towards Portsmouth Harbour Station, the area targeted for drastic transformation. Admittedly, it may not be everyone's idea of paradise, but I like it, particularly the station, which enters the water on stilts. Even in Febuary the whaft is busy with Isle of Wight ferries. Beyond is the lovely Georgian church of St George's.

Open the lungs, swell the chest and head at a brisk pace down Gunwharf Road, White Hart Road and round into The Point. Here is Spice Island, where sailors came to let down their hair and much else besides. Outside the city walls and therefore beyond the reach of law and order, Spice Island once boasted more than 40 inns and alehouses plus numerous houses of ill repute. Today, there are just three pubs - and I couldn't discover a single disreputable house.

No matter - stroll around this delightful peninsula and revel in the sins of bygone days. But make sure you don't miss the Round Tower and its colleague the Square Tower, which squat on the old curtain wall and remind us that the matter of defence and fortification were deadly serious.

Wander up the High Street, catching a glimpse over to the right of the old Garrison Church where Charles II married his bride from Portugal in 1662. His father's favourite, the Duke of Buckingham, had met a violent death in the High Street in 1629 when stabbed by an aggrieved soldier.

On your left is the too little-known Portsmouth Cathedral, once a parish church and bombarded during the English Civil War. A cathedral since 1927, its fine new west end is a sympathetic piece of modern architecture.

At the top of the High Street, past the Grammar School, is a roundabout. Over to the left is the Land Port gate of 1698, one of the former entrances into Old Portsmouth. Turn right down Museum Road toward the old barracks, which now contain an excellent museum and art gallery.

Landport Terrace is smart, professional Portsmouth. Walk up it and along Hampshire Terrace back toward the city centre. The exotic building on the right is a former cinema built in 1924 and designed by an architect who had just returned from the Khyber Pass. Almost opposite is the attractive White Swan pub and, after it, the Theatre Royal with its exterior balcony on stylish cast-iron legs.

Ahead is the rear view of a distinctly dumpy Queen Victoria who faces the Guildhall. The walk ends back at the station, over to your left.

Length of walk: two and a half miles (excluding detours)

Tourist Information Centre: The Hard (01705 826722)

Charles Dickens' Birthplace Museum, Old Commercial Road, open March to October, daily 10am-5.30pm, adults pounds 1.10, concessions 65p, under 13s free (01705 827261).

Portsmouth Historic Dockyard open daily, November to February 10am-5.30pm, March to October 10am-6pm. Inclusive ticket for all four ships: adults pounds 10, children pounds 6, senior citizens pounds 9 (01705 733060).

Portsmouth City Museum and Art Gallery open daily, 10am-5pm, except for Christmas Eve, Christmas Day and Boxing Day. Admission free (01705 827261).