Mezquita-Cordoba

When I went, an advanced ticket was required, but this was just post-pandemic.

But all that meant was when I arrived at the venue, I went on the app for the sight and bought the ticket. While crowds probably vary during the year, I doubt they ever "sell out", so you could likely wait until you get there to pick a convenient time if you are unsure of schedule.

Added: Just looking quick, it does not appear advanced booking is still required. I think in my case, it was a measure to limit interaction with staff for safety reasons.

No recent experience, but in the few times we’ve been there no advance tickets were needed. I’m sure there are times of the year when it’s extremely busy and advance tickets would be helpful. We don’t schedule our trips to the point where we know exactly when we’ll be going to a specific site and we don’t travel during the high travel season.

It depends on your patience with queuing. If you’re going during high season and during midday, you’ll wait in line for a bit without one. Pick slack times and you’ll breeze in.

There is a separate ticket for the minaret/bell tower; also timed. It’s interesting, but nowhere near as cool as the actual mezquita.

Just visited, early March 2024. Some of the times on my day were sold out. If you don’t have a specific timeframe, it would have been possible to purchase last minute for an available time slot. I was glad I had pre-purchased as my time was limited and had to fit into a broader schedule. I was not allowed in before my stated time - I tried.

This was “low season”. I would pre-book for busy times. You can easily monitor ticket availability on the purchase page.