Cordoba:well worth it
To say its hot here is an understatement. Its about 37°C (99°F), as this is being written. The saving grace is humidity levels on a par with Arizona.
It makes your eyes dry.
Moan moan
But there's some spectacular stuff here. About 200 years before the Ottomans conquered constantinople and changed most of the existing churches onto mosques; the reconquista turned most of Cordoba's mosques into churches.

The cathedral has the most fantastic arched interior. Like the cathederal in Toledo, it too covers all of the ground covered by the preexisting mosque.

The streets which surround the cathedral are similar to those in old towns on the north and south coasts of the Mediterranean.
You can see a walk we took through to and around the cathedral here.
Many are built to be 4-6ft (1.4-2.0m) wide, keeping the pathways through relatively cooler than the modern roads designed for cars, which can be much hotter.
The Gardens of Alcazar would have been something special, if you'd flogged your way here across the dusty interior on foot or horseback. They would have been a welcome splash of green in the desert-like landscape which is all this part of Spain has to offer.

The Romas were here too with a surviving bridge and a ruined temple.
But, its been too hot. Our days start at 0730 with breakfast in the hotel, then exploring for a couple of hours to 1100 or 1200. We skulk in air-conditioned bliss untill its early evening. Then scuttle out to a bar for a drink and something to eat.

This is about as warm as we're going to get.
Our itinerary now includes Huelva and then Albufeira, Portugal for a couple of days as we turn north again and start making our way back to Santiago.