The closest airport is Jerez de la Frontera, approx 30 minutes by car or taxi (fixed price €46), 1 hour by direct bus. There are several daily flights to Madrid and Barcelona (Iberia, Spanair, Vueling). Ryanair flies daily to London Stansted and Frankfurt Hahn. Other operators fly scheduled, charter, or seasonal flights. The nearest major airports are in Sevilla (hour by car, 2 hours by bus or train) and Malaga (2-3 hours by car or bus).
Frequent trains run to Jerez and about hourly to Seville. A very convenient way to come in from Madrid is with the Talgo train that runs twice a day covering the distance in about 5 hours. See RENFE for timetables.
From Madrid, Cordoba and Seville you can use the A4, from Barcelona N340. A taxi ride from Jerez de la Frontera to Cadiz costs about € 50.
Cadiz is said to be the oldest city in western Europe, as it was founded by Phoenician sailors about 3.000 years ago, as a commercial stronghold. Archeological remains can be found all around the old town. The Archeological Museum (Plaza de Mina) exhibits are interesting, specially two Phoenician stone sarcophagus. The remainings of the Roman theatre just behind the cathedral are also worth a visit.
The massive stone walls and forts that can be seen surrounding the old town were built to protect the city after the British attack in 1596, and the forts of San Sebastian and Santa Catalina are open to the public.
Everyone should visit the Cathedral in the old town and climb to the top of the cupula for a nice view of the entire city.
The Torre Tavira, near the Central Market (Mercado de Abastos) holds a "camara oscura". Located in one of the towers originally used by merchants to watch out for their ships returning home from the Americas, it provides a birds-eye view of the old part of town.
The Central Market itself is well worth a visit in the morning, especially the fish section, but it will be closed for repairs until the end of 2008.
A modern monument of Cadiz are the huge pylons of the powerline crossing the bay of Cadiz. These 150 metre high pylons are lattice towers with cylindrical cross section.
Do not miss Carnaval in Cadiz, one of the oldest and best in Spain, often cited as the third biggest Carnaval celebration in the world. Usually in February, the weekend before Ash Wednesday is consistently the loudest and most eventful so be sure to check the calendar. Singing, dancing and costumes run until Fat Tuesday (the day before Ash Wednesday). Informal groups (chirigotas, cuartetos, coros, comparsas and romanceros) sing at the old town streets, usually with strong critics on local, national and international politics, the jet set, and just about anything/anybody, up to the Royal Family. Make your travel plans early as most accommodation gets booked months in advance and be prepared to spend almost double for the week of Carnaval. One way to experience Carnaval on the dime, and perhaps the preferred way of Andalusian locals, is to board an afternoon train heading to Cadiz, spend the night singing and dancing, then catch the first train back in the morning. Expect singing, dancing, costumes and drinking on all trains. Sleeping on the public beach is also another popular option, though be sure to bring a blanket or sleeping bag, both of which can be stored in lockers at the train station; expect company and use common sense.
Semana Santa (Easter or Holy Week) is less formal than in Sevilla, and probably more authentic and emotive an experience for that.
Enjoy the best sunset in Spain at 'Playa de la Caleta' at the northern end of the old town. The main beaches (Santa Maria Del Mar, Victoria, and Cortadura) start at the edge of the old town, continue all along the new town, and on alongside the road to San Fernando. In total some 10 km of the widest, cleanest beaches you will find in Europe, with safe bathing from around May to October. The summer heat is usually tempered by an Atlantic breeze, although on days when the Levante blows beware of flying sand.
Standard souvenirs can be found at several shops in Calle Pelota, Calle Compañía, Calle San Francisco and Plaza de Candelaria.
In Cadiz you will find some of the best and freshest fish and shellfish in the world. They are best eaten as simply cooked as possible: plain boiled shellfish (in varying sizes from tiny prawns up to lobsters), grilled or baked whole fish such as lubina (bass) or dorada (bream), or deep fried with a light flour coating (especially puntillitas (baby squid) and boquerones (anchovies).
To eat not too expensive fish and shelfish, you can look at Calle Zorrilla (several tapas bars and street vendors) or Calle de la Palma (several restaurants with open air terraces).
For a splurge, the best place in town is Restaurante El Faro (Calle San Félix. But even here food can be not very expensive, if you stand at the bar and eat only tapas.
Fino, a bone dry sherry (or Jerez), or manzanilla, a similar wine from Sanlucar de Barrameda, is the perfect aperitif with olives or a prawn or two. Drinking more than a couple of glasses may spoil your focus on the rest of the meal. The best local white wine (and one of the most popular in Spain) is Barbadillo, made from the same grape but considerably lighter.