Traditional ferries take about 5 hours in the day and 8 hours in the night from Portsmouth, although there is also a 2 ¾ hour journey that can be taken on the Portsmouth Express. If you are in Paris you can take the N13/A13 dual carriageway/autoroute which also links to the A84 autoroute that is still under construction to Rennes.
The old basin, the fishing port, is the centre of the old part of Cherbourg. Although there are no Roman remains to be seen, old Cherbourg's history goes back to the Roman times. The town is also overlooked by the 'Fort du Roule', giving fantastic views of the town when it is a clear day.
Rather than simply rushing through to or from the ferry or the hypermarket it is worth spending time in the town to pass the day with a number of activities such as the new "La Cite de la Mer", which opened in 2002 as a cylindrical acquarium and former nuclear submarine in the former trans-Atlantic terminal building.
There are not huge shopping facilities in the town, however you can find bargains in the large number of smaller shops that lie near the waterfront in a maze of nice narrow pedestrianised cobbled streets. These shops are packed with specialist wine and food shops, restaurants, cafes, gift shops and fashion boutiques.
There are also street markets. The Place De Gaulle is close to the theatre and the fountain, and is open on Tuesdays, Thursdays and Saturdays. This market is good for fresh produce whilst the Cherbourg Old Town (La Vielle Ville) offers fish as its speciality.
EuroDif, near the main square, is the largest department store around, with three floors packed with typical French merchandise, such as clothing, fabrics, haberdashery, crockery, bed and table linen, other homewear and candles.
On the outskirts of town you can find the large hypermarkets such as Carrefour at Octeville, which is located on the edge of town when you leave the main N13. Leclerc is in Tourlaville and the Auchan is on the N13, on the route to Caen and Paris.
There are also a wide variety of restaurants offering all sorts of food at all sorts of prices - from seafood to crepes to Pizzas and Salads, most of which can easily be found on a walk from the waterfront. You'll also find that shops and banks will be open earlier and will close later than the UK.