This route follows the western sea wall of the old town from the north end of La Caleta round to the cathedral. It takes in Castillo de Santa Catalina, the promenade of La Caleta, the causeway to Castillo de San Sebastián and the whole of Campo del Sur. The total is about 4 km with the causeway and 2.2 km without it, and it takes 3 to 3.5 hours with stops, of which roughly an hour is walking. Both figures are estimates from map coordinates along the paths, not a surveyed trail.
Start at Santa Catalina, the star-shaped fort Philip II ordered after the English and Dutch attack of 1596. Entry is free except on days with announced events, and the council lists 11:00 to 19:00 in winter (1 October to 31 March) and 11:00 to 19:30 in summer. From the gate the promenade runs south along Avenida Duque de Nájera beside the 450 m of sand, a little over half a kilometre to the point where the causeway leaves the shore.
The causeway is the longest single stretch: about 900 m each way, so nearly 1.8 km out and back, flat and with no shade. The castle is joined to the land by a stone causeway, which is why it stays reachable at high tide, and the present jetty dates from the 1860 works. The Ayuntamiento lists the castle as open daily from 9:00 until sunset, free, subject to the weather. Check that on the day. If it is shut, skip the causeway and the walk drops to 2.2 km.
Back on shore, the Baluarte de los Mártires stands at the crossing of Duque de Nájera and Campo del Sur. It dates from 1676, but a restaurant venue now hides most of its original outline, and concrete blocks at its foot form an artificial reef against the swell. Campo del Sur starts here. The city's tourism site calls it the malecón gaditano and recommends taking it slowly, with the Atlantic breaking on the wall and the cathedral ahead. El Faro de Cádiz is a short step inland on Calle San Félix if you want tortillitas de camarones halfway; check its hours before you plan around it.
The wall runs east for roughly a kilometre to the cathedral, whose golden-tiled dome you will have been watching for most of the walk, and the Roman Theatre sits just behind it. The route ends at the Casa de Iberoamérica, the former Cárcel Real, another 500 m on. It opened as a municipal cultural centre in January 2010 and works here as a clear end marker rather than a visit.
Legs, as the crow flies along the paths:
- Santa Catalina to the causeway start: 0.6 km
- Causeway to San Sebastián: 0.9 km each way
- Causeway start to Baluarte de los Mártires: 0.1 km
- Baluarte de los Mártires to the cathedral, via El Faro de Cádiz: 1.0 km
- Cathedral to Casa de Iberoamérica: 0.5 km