Why go now?
Because the fragile facades of Lisbon, which endow the Portuguese capital with such soul, are crumbling rapidly beneath an onslaught of modernity: while half the city is being dug up for the new subway, the other half is being refurbished for next year's Expo. New, cheap flights have opened up the city as an accessible weekend destination. And it's one Continental capital where you don't have to adjust your watch.
The lowest fare to Lisbon is likely to be on AB Airlines (0345 464748) from Gatwick; flying next weekend, the cheapest return is pounds 131 including tax. Portugalia (0990 502048) flies from Manchester, but not at weekends; leaving next Friday and returning on Monday costs pounds 201. British Airways (0345 222111) and TAP Air Portugal (0171-828 0262) fly from Heathrow.
Get your bearings
The helpful tourist office outside the customs hall at the airport (open 6am-2am) will provide you with a map of the city. The Aero-Bus runs to the centre between 7am and 8.40pm daily; as Lisbon airport is so close in, a taxi costs only pounds 4.
The city sprawls along the north shore of the Tagus, but you need focus on only three basic areas. The flat part in the middle is Baixa (pronounced bye-sha). Rising to the west is Bairro Alto (approximately biru altu), and to the east Alfama.
Aim for the centre. Bairro Alto and Baixa have plenty of modest options; in the former, the Pensao Londres (rua Dom Pedro V 53, 00 351 1 346 2203) charges 6,200-9,200 escudos for a double room, corresponding to pounds 21-pounds 31. In Baixa, the Pensao Insulana at rua da Assuncao 52 (00 351 1 342 3131) offers good value at 8,500 (pounds 29) per night, including bathroom and TV. Breakfast is included in all these rates.
Take a ride
Tram 28 is one of Europe's great little journeys - an exercise in kinetic eccentricity as it sways up improbable gradients and squeezes through impossible gaps. Summer visitors missed out on the full glory of the route, but track repair work has now finished. For 150 escudos (about 50 pence), ride the whole, hilariously convoluted journey from Prazeres, west of Bairro Alto, to the square named Martim Moniz (north of Baixa).
Take a hike
The tram reveals Lisbon to be defiantly three-dimensional. From its eastern terminus, steer a southerly course to touch down amid the swirl of traffic around Baixa. Stay on the same heading, and soon you reach the foot of an Eiffel-designed lift called the Elevador Santa Justa. It hauls you from humdrum sea level to a higher plane. Sadly, subway work means you can't step deftly from the viewing platform into Bairro Alto; instead, descend again and wend your way there on a warm autumnal walk.
Lunch on the run
By the time you huff to the top end of rua Garrett, you'll need a coffee and pastry. The fine old Cafe A Brasileira, half hidden by subway hoardings, is a grand hall of age-darkened wood and fresh, young faces reflected in a million mirrors. Lisbon's intelligentsia natters here for hours.
Lisbon's chief civic characteristic is nattering in cafes, but there is also a streak of diligence - manifested at the Museu da Agua. Take a taxi to avoid a long, frustrating walk in an area where few seem to know of its existence. The reward is a palace of engineering, a frenzy of brass and steel in a former pumping station built in the days when municipal magnificence was mandatory.
The funniest piece of public transport in Lisbon is the Elevador da Bica, in which a lop-sided tram shuffles up and down a steep gradient. Near the top end is Work in Progress, an intriguing combination of clothes store, hairdresser and ( possibly crucial as dusk gathers strength) a jolly bar.
Yet another Elevador - this one named Gloria - elevates you to the Solar do Vinho do Porto (Port Wine Institute). Subside into the deep leather armchairs of this handsome chamber of commerce, and choose something white and chilled from among hundreds of varieties of port.
For quiet elegance, best stay at home; Bairro Alto on a Saturday night is not a peaceful place to be. But it possesses a staggering selection of restaurants on and around rua do Diario de Noticias.
Sunday morning: go to church
But don't go in. Lisbon's cathedral (which yesterday's tram had to swerve to avoid) is mostly memorable for the views from its south side over mottled terracotta roofs towards the broad Tagus - spanned, in the distance, by the 25 April Bridge, doing its best to mimic San Francisco's Golden Gate.
A walk in the park
The stridently ramped nature of Lisbon means its principle open space, named in honour of a British monarch, is guaranteed to yield grand prospects. An heroic new sculpture presides over the vast Eduardo VII park, prime picnicking territory that shelves gently down towards Baixa.
The icing on the cake
Tram 15 whisks you out west to Belem. Some misguided tourists come here for the Archaeological Museum or Jeronimo Monastery. But everyone eventually ends up at Pasteis de Belem, a patisserie whose pastel (the sole product: an exotic custard pie with attitude and icing sugar) is miraculous and more-ish, like the city itself.