3 of us will be traveling through southern Spain the last 2 weeks of May. I am having trouble figuring out whether it is helpful, to avoid long lines, to pre-purchase some of the admittance tickets:
Palacia Real Madrid
Alcazar Seville
Church of El Salvador & Cathedral Seville
Cathedral & Capella Real Granada
I did know that I needed to get my Alhambra tickets, and those. Yeah!
Thanks for any help/thoughts with this.

In September we visited all of the places you mention, except the Church of El Salvador, and we DID NOT pre-purchase any tickets, except of course for the Alhambra. I prefer not pre-purchasing tickets because we like the freedom of deciding what we are doing when we wake up in the morning. I don’t like my vacation to be that regimented.

What worked for us is being at most sites about 30 minutes before opening time. That’s what we did for the Royal Palace in Madrid, the Seville Alcazar, and the Seville Cathedral. However, We arrived in Granada in the late morning, and walked into the Granada Cathedral in mid-afternoon. No lines at all.

Thanks, we prefer not to be tied down either, that is why we didn't want to buy the ahead unless we really needed to

We purchased advance tickets only for the Alhambra and the Alcazar. You might consider adding tickets for the Alcazar if you want to see the Royal Apartments as those tickets are quite limited.

I was in Sevilla two weeks ago. I was shocked by the length of the line to purchase entry tickets to the Alcazar, and there was a similar line for the cathedral. I have no idea how long people waited to get in, but we had pre-purchased entry to the Alcazar (and the Royal Apartments) and sailed right in. If I recollect properly, the entry point for prepaid ticket holders is to the left of the ticket purchase office.

If you decide to add on the Royal Apartments (a brief but interesting tour), you need to be at the security check point for the apartments about 10 minutes before your tour starts. They check your ticket, scan your stuff, and give you an audio guide. Once the group is escorted into the apartments, there is no further entry until the next scheduled group goes in.

I can't offer any advice on the cathedral in Sevilla, as we had decided to give it a miss.

We also visited the cathedral in Granada, and had the same experience as KarenWoo; we just walked up, bought our tickets, and entered.

A word about the Alhambra: having pre-printed tickets, we entered at the Justice Gate. There is a booth outside the Nasrid Palace that rents audio guides. The young man at the booth was extremely helpful, but the process is glacial; it takes a couple of minutes per device to get it activated and to explain how to use it. So, if your timed entry is for, say, 9 am, and you wish to pick up an audio guide there, you might want to build in a little time for the transaction.

Even though the lines look long, we didn’t wait too long once the site opened and started selling tickets. The lines moved fairly quickly. I think the most important thing is to arrive at the site about 30 minutes before it opens. I do remember walking past the Seville Cathedral in the afternoons and the line was huge! Much longer than it was when we arrived 30 minutes before opening.

I agree with AnselmeAdorne about arriving early at the Alhambra. We were there about an hour before our timed entry. We also entered through the Justic Gate. This gave us time to purchase the audioguides, use restrooms, and quickly see a little bit of the Charles Palace.

The week we were in Sevilla the Cathedral had several times when it was open for free. Sundays for sure, but there were all kinds of festivals and the doors were opening and people just walked in. Agree with all who say get tickets for the Alcazar. Like Anselm I was absolutely floored by how long the lines were at this time of the year. Our apt was right near there and in February the lines for those without tickets was long whenever we walked by. For some reason Thursday morning there was no line. We bought our tickets online a couple days in advance. We went to the Royal apts and would give them a miss. We weren't impressed after everything else we had seen. I would think that at the end of May, it will be much more crowded everywhere.

Hi AA! Assume you are home by now?

Hi yestravel. We flew from Madrid yesterday morning, spent the night in Toronto, and walked in our door about two hours ago. It was a great trip!