Mosque of Cordoba

I'm not sure why it wouldn't be. Perhaps you are thinking it is a mosque? It was historically, but is now a Catholic cathedral. Or perhaps you are concerned about specific terrorist threats in Spain? The State Department keeps a running list of threats and high risk areas on it's website. Never a bad idea to check that before traveling. Spain has had a history of terrorism and separatist movements, but as far as I know, Cordoba is not been a part of that.

As safe as any trip to any city. Remember your greatest risk to bodily injury is the drive to and from your home airport. I would not worry about it.

Very good. I do check the State Dept for warnings. Yes, it is still called a Mosque- Cathedral online.

Thanks so much.

Yes, no problem to see it and well worth the trip, give yourself six hours to see the Mesquita and surrounding quarter (there's also a tiny, very old synagogue). It's not walking distance from the train station, you can either taxi or use a public transit bus to get to the Mesquita.

'It's not walking distance from the train station' - It's fine for me at 25 minutes with 60 year old legs :-)

^^ I have younger legs, but agree it is perfectly walkable unless you have a mobility impairment. Figure about 30 minutes as there is much to see along the way. And you'll need a good map as the streets of the old center are pretty twisty. There is also a more direct route following the large park along the old walls.

Visiting the Mezquita is perfectly safe, as safe as visiting any other tourist site in Spain. It's a pleasant 25 min. walk from either the train or bus station to the Mezquita through the Jardines de la Victoria park. At the end of the park, you will cross a street and head toward the old city walls, which you can follow down to the Alcazar. From there, calle Amador de los Reyes leads directly to the Mezquita. If you don't want to walk, a taxi from either station to the Mezquita costs about 7 euros or you can take bus #3 for 1.20 euros (buy ticket from driver and ask for Mezquita).

Perhaps the greatest danger is to your legs (from walking) or to your neck (from looking up at the marvellous arches).
Another potential danger is getting lost in a tapas bar having a few sherries and missing your train back to Madrid!!

It's not that you can't walk it, it's that it consumes too much of your limited time walking there and back. If I have six hours, I don't want to spend an hour of it walking through an average looking city to get to the old center and back. I want to spend my time in the old center. I agree the roads are narrow and twisty in the center, a map of the area will help a lot.