I went very late. in the day and it wasnt bad at all. I heard everyone comes early so I did the opposite and went 30 mins before closing. Seemed like everyone had went in already and hanging around the area.

A la torre le daría una hora y a la catedral dos

The bell tower is about 7 floors tall with reasonably steep steps, there is a balcony to stop by after about 5 floors. You need to buy tickets is advance, since they get sold very fast. They only allow 25 people at a time every half hour. The best option is to buy the combined ticket online from the Mesquita website. The top of the bell tower provides a nice view of the river and the old town. One can also see the gradual / incremental development of the Mesquita over the years from the top.

Well, I didn't hire a guide or a guided tour to visit the "Mezquita-Catedral de Córdoba". I bought the entry ticket (E$10) right on arriving, received a small booklet with enough information, including a simple map of the of the complex. But you see groups and guides in the premises. Not having a guide may allow you to enjoy this magnificent site at your own rhythm at no hurry. Unmissable! Enjoy!

Es wird jeden Morgen ein Gottesdienst abgehalten.

Yo te recomiendo la visita guiada... ahí es donde aprendes y sabes más cosas de cada monumento!!!

Si, de 8.30 a 9.30 se puede visitar gratuitamente, la entrada es por las puertas laterales, situarse delante de la puerta central y vaya rodeando la mezquita hacia su izquierda , la segunda puerta es la que abren a las 8.30

È talmente spettacolare che ti consiglio entrambe le visite...io sono appena tornato e ci sono stato quattro volte in due giorni....approfitta di un primo esplorativo la mattina presto che spesso è gratuito e con poca gente anche se non sufficiente per vedere tutto

Contact the touristoffice of cordoba resp. the management of the mezquita/city of cordoba.