Happy Birthday, Cambridge

Lunchtime is fast approaching and the silver is being laid on white linen in the dining hall at Magdalene College. Clank. Clink. Chink. But in Dr Richard Luckett's rooms we do not hear a thing.

His sanctuary is insulated by bastions of stone, plaster, wooden shelving and thousands upon thousands of books. Here, the outside world is held at bay, as it has been in Cambridge for eight centuries. It may enter this particular nook of the city only with Dr Luckett's express permission.

It is important not to read this insularity as isolationist. The outside world is not unwanted. Far from it: Cambridge knows it must accommodate the worldly world. But ours is a discretionary presence – we are welcome, but strictly on Cambridge's terms. "Ah. Well. Yes." Dr Luckett is a distinguished man and his manner of speech fits him. He is the Pepys Librarian, the scholar responsible for the wordly residue of our most celebrated diarist, all of it contained in the Pepys Library up a different staircase in the same building at the back of the College. "We do try to make sure that the things we have out on display [in the Library] have some sort of current relevance. For instance," – an introvert smile steals across his face – "we have out at the moment a ballad entitled 'The Silver Age', from 1623, which laments the economic iniquities of the period. In particular, it laments the iniquity of usury ...".

As to the matter of public access to the Pepys Library and related topics, I am referred by Dr Luckett to "a greater authority", which I take to mean my mother, who was the Assistant Librarian in The Pepys for much of her working life. You see, time presses and Dr Luckett has to fly. The Fellows' Christmas lunch is about to be served; it is even now making the short journey from kitchens to Hall on its silver salvers. I have to content myself with the memory of what the Library looked like in the 1970s, every book arranged by size, from volumes one (the smallest) to 3,000 (the biggest) on shelves that Pepys himself designed.

The memory will do fine. After all, it is certain that the place itself will have changed not at all. Cambridge University is celebrating its 800th anniversary this year, which means that the city of Cambridge is having to celebrate it too. This is not unreasonable, given that the city owes its state of touristic luxury to the academic institution which settled there, somewhat haphazardly, not long before the signing of Magna Carta, in 1209. It was founded by scholarly clerics in search of the "peace, independence and freedom" that insularity is often thought to bring. The city is outwardly indivisible from the university, and always has been. This has long given rise to internal friction. The town/gown division is a strange, invisible thing felt only by townies and gownies but grossly exacerbated at both social and economic levels by the fact that the University owns the vast majority of Cambridge real estate and is therefore in a position to influence who lives and works where, on what terms and in what conditions.

This inequity is further complicated by the fact that the University isn't a single organism (except, shallowly, at Senate level) but a collection of smaller ones operating in their own interests, harnessed by some vague notion of the general good. The upshot is that the colleges divide and the colleges rule. The "town" simply has to get on with it and exploit the benefits, such as they are.

They are considerable, as it happens, even for those souls constrained to live out of sight of the centre in estates cached on the fringes of the city. There are no two ways about it: central Cambridge is lovely to behold, even if the precinctification of the Sidney Street/Lion Yard retail nucleus is as grimly bland as any in the UK.

I am biased, of course. It's my home town. I haven't lived there in 30 years but I still miss its peculiarities: the way the city's ancient surfaces serve as a gorgeous backdrop to ungorgeous behaviour. For there is no social climbing like academic social climbing. It is certainly true to say that every memory I have of being young in Cambridge has a great look to it, from the embrace of maidens among the willows of Grantchester Meadows to rejection at the hands of one particular maiden on the doorstep of the President's Lodge at Queen's College, where she lived. It was the best-staged and lit humiliation of my life. The fact is, you cannot be in Cambridge and not feel as if you are mincing around on the set of someone else's drama – which is one of the reasons for the city's abiding status in the top 10 of the UK's tourist premier league. But you do need to know the ropes.

For a start, the best bits are not all that obvious. Yes, there's the Fitzwilliam Museum, Kettle's Yard gallery, the Scott Polar Research Institute, the Whipple Museum (of the History of Science), the Museum of Archaeology and Anthropology, the Corpus Clock, the Round Church, King's Chapel, the Folk Museum, the Botanic Gardens, The Eagle pub and, of course, punting on the Backs. All of them are fabulous to one degree or another but all of them also amount to a list of the bleedin' obvious.

The subtler pleasures of the city are harder to extract. For much of the spring, access to colleges is restricted to some extent, depending on a handful of variables to do with exam timetables and proximity to the Backs. King's, Queen's, Trinity, St John's and Clare Colleges – all of them giving directly on to the River Cam – are burdened with the most beautiful rear aspects of any buildings in England and so have found it prudent to charge visitors for the privilege of breathing their in-season air.

And why not? Cambridge colleges are not museums; they live and breathe as well as look pretty, and it is their duty to insulate the labours of their undergraduates. But it remains an awkward fact that ordinary folk can come and go relatively freely among most of the colleges most of the year round. Private areas are always clearly marked, once you're in. But it's getting in that often proves daunting: those of self-effacing nature may not find it easy to insinuate themselves through gnarly posterns and porters' lodges into what feels like someone else's private domain.

Well, it is and it isn't a private domain, and that's where the difficulty lies. Colleges are obliged to make themselves accessible but on the whole would prefer it if they were allowed to get on with their activities undisturbed – which is why they don't make themselves inviting. But be brave and be quiet, polite and observant of the regulations (stay off quad grass!) and all will be well.

And make sure you go to the Visit Cambridge information office in Wheeler Street first. Cambridge is such a complex, occlusive structure, it really is worth orientating yourself with a map. There is, of course, a multitude of events planned for the 800th anniversary celebrations and, this being Cambridge, they will be idiosyncratic in both their content and their execution. But actually, Cambridge doesn't need events to make it sing. It is above all a place of atmosphere. Whether you're gingering up the staircase to the Pepys Library or mooning at the river on Jesus Green, just suck it up and feel the privilege – yours as well as theirs. And if you must punt, head for Scudamore's in Mill Lane and steer south towards Grantchester. The willows there really are exceptional. Plus, there's the Orchard Tea Garden, where you can recover your poise among the apple trees, just like Rupert Brooke. Or Pink Floyd.

Something I always try to do when in Cambridge is have a Chelsea bun in Fitzbillies in Trumpington Street. Today is no exception, and I am soaking up the blue of Cambridge's winter dusk. Cambridge is a city of saturating light, especially at the end of a short bright winter's day, and for some reason the blue transports me back to the afternoon I stood on the cracked paving stones of Queen's Lane, gritted my teeth, slipped through the postern, crossed cloister and quad to the door of the President's Lodge in Queen's College and knocked,

Queen's Lane is only round the corner. No harm can come from revisiting the scene of one's grimmest failures, surely. Come on. It would only take a minute ...

Five attractions not to miss in Cambridge

King's College Chapel: If Cambridge has a visual signature then the Gothic horns of this remarkable structure are it. You used to be able to wander in at will. Not any more. King's is one of only two colleges with a year-round entry charge (the other is St John's).

Trinity College: One of the grander colleges backing on to the river. But be warned: it is likely to be closed for works for much of 2009. All the more reason for you to brave the porter's lodge at its much prettier but harder to find neighbour, Trinity Hall.

The Backs: Punting is not as easy as it looks. But it is one of the more romantic things you can do over a long summer day – especially if you zigzag in a southerly direction towards Grantchester.

Fitzwilliam Museum: One of the best, and most overlooked, provincial museum/galleries, worth the trot down Trumpington Street for its special exhibitions, its Titian, its medieval art, its armour – and for its notorious Ming vases, above. If you want to know why they're notorious, just ask an attendant.

Corpus Clock: Cambridge's latest attraction is this burnished timepiece set into the corner of Corpus Christi College, designed by Dr John C Taylor "to depict time as a wave coming out of the centre of the universe", surmounted by a grasshopper or Chronophage. But of course it is.

Compact facts

How to get there

Nick Coleman travelled to Cambridge with First Capital Connect ( www.firstcapitalconnect.co.uk).

Further information

Cambridge tourist information ( www.visitcambridge.org); University of Cambridge 800th anniversary ( www.800.cam.ac.uk); East of England Tourism ( www.visiteastofengland.com).