You can do Cordoba in 2 days.
Use Booking.com to look for hotels and apartments in The Real Heart of Cordoba. For those making a day trip to Cordoba, the train station does not have luggage lockers but the bus station beside it has luggage lockers. A taxi to the Mezquita will cost only about 6 euros because the distance from the train station is only 1.8 km.
The best sights in Cordoba:
1. Mezquita/Cathedral - The most important architectural feature of the Mezquita are the double horseshoe arches, made of jasper, onyx, marble, and granite. There are 856 columns in the church and they seem to be a sea of arches and columns to the visitor.
2. Alcazar de los Reyes Cristianos - Has beautiful gardens.
3. Palacio de Viana - The palace has important artwork and there are 12 different patios, all beautiful.
Good restaurants near the Mezquita:
1. Casa Pepe de la Juderia (Calle Romero, 3; Tel: 957-200-744).
2. El Caballo Rojo (Calle del Cardenal Herrero, 28; Tel: 957-475-375).
Shopping streets are the area around the Mezquita, Calle Jose Cruz Conde, Ronda de los Tejares, Conde de Gondomar and Avenida de Gran Capitan.
Dress code for churches: Shorts or bare shoulders are not allowed for either women or men. The Mezquita is a Catholic church.
In May, the Courtyards (Patios) Festival takes place. This has been in the Unesco List of Intangible Cultural Heritage since 2012. This is also one of the most colorful and enjoyable festivals in Spain. Do not miss it. The dates change every year. Traditionally it takes place on the first and second week in May.
Depending a bit on the season because you may find the city has more going on at certain times of the year. If you have no specific time constraints then at least 2 nights and 3 would give you best opportunity to explore. The old Moorish town site of Medina Azahara or as Trip Advisor say Madinat Aĺ Zahra could appeal and you can take the local bus organised by tourist office. Read more
I just got back...had 3 nites and 2 full days there. it was perfect!
We used the Hotel Eurostars Palace, easy walking distance but picked by us for its secure underground parking.
Also has an excellent roof top bar and pool area if that interests you.
Two nights, one full day is enough for visiting the Cordoba attractions.
Pay attention that on Monday many attractions are closed and on Sunday, only partially opened.
Medina Azhara is outside the city and can be visited before the first night or after departing.
One full day is enough.
If you have a car, I would recommend an excursion to almodovar del rio (opens at 11). 20 minutes away, an amazing castle situated on top of a hill. Free parking and 8 euros for admission. Spent about an hour walking through all the corridors and towers. Fantastic views of the countryside. Made it back to Cordoba for lunch at Mercado Victoria!