I visited this WHS in September 2017. Together with Granada (and most probably Seville), this WHS is not only Andalucia's highlight but perhaps Spain's if not Europe's. It has definitely earned its place on my personal top 100 WHS.
The iconic red and white arches of the Mezquita are so iconic (photo) and there are hundreds of them in the gigantic mosque-cathedral of Cordoba. But Cordoba is much more than that. The exterior of the huge Mezquita is as impressive as its interior. I particularly enjoyed the different puertas with their intricate red and white carvings and doors. Another gem is the 15th century Capilla Mudejar de San Bartolome, neatly hidden amidst the famous shaded patios with numerous pots and plants.
The view from the bridge and tower are worth taking in. Perhaps the best thing about Cordoba is that it has a natural buffer surrounding it which is the Sotos de la Albolafia Natural Park. There's a short trail which takes you from one mill to the next on the Guadalquivir river banks. The UNESCO WHS inscription plaque is just to the left of the bridge (if you cross the bridge facing the Mezquita). If you love gardens, then go for a short visit to the Alcazar de los Reyes Cristianos (closed on Mondays).
Even though the entrance to the Mezquita costs 8 euros, you can visit for free from 08:30 to 10:00 every day. After your visit to the Mezquita, make sure to pop in Casa Santos for a generous helping of their signature tortilla de patatas and a beer. I had a great time in Cordoba and I'll most probably revisit soon when I return to Andalucia to visit Seville and Donana NP.