Working on itinerary for approx. 16-17 day multi-city visit Sept/Oct. Of course, we'll have a few Mondays and so on short visits to cities I'm trying very hard to figure out when museums are open/closed. For example, since we are staying 2 nights but only 1 full day in Toledo, that full day cannot be on a Monday because it's clear that the El Greco museum and the synagogue are both closed...so I presume smaller cities have an across-the-board closed-on-Mondays policy. Does this hold true in Barcelona, Sevilla and Madrid?

In most big and small cities museums are usually closed Mondays,
but you better check.
In Madrid , Reina Sofia is closed Tuesday
Prado is closed only on certain holidays

If there is some place you want to go, I would check the website, not just assume. Yes, most museums in Spain are closed Mondays, but not all. And of course, that doesn't mean most other places of interest are closed on Monday (non-museums). In some big tourism cities, some things are open every day.

Outside Madrid, El Escorial is open every day.

In Seville, the Fine Arts museum is closed Monday, as are the Arts and Traditions museum and the Navigation Museum (this is not the Toro del Oro). The Flamenco museum (which was really good) is open every day, as is the Alcazar and the Casa de Pilatos.

And some museums are open shorter hours on Tuesday or Sundays, so you need to check hours of any place you most want to see. In Cordoba, the archeological museum is only open from 3 pm and later, for example. In Madrid, the archeological museum closes at 3 pm on Sunday.

really helpful. thanks so very much.

Another big concern is where to eat on Sunday and Monday. A lot of restaurants are closed for dinner on Sunday and all day Monday (why open when the seafood isn't fresh?). Some close on Tuesday or Wednesday, so it's best to check and plan ahead. Don't expect to be able to make a meal of (haute cuisine) tapas, especially in places where the culture doesn't exist.

I agree -- check the websites, and be sure it is the actual website for each place that interests you, as there are lots of sites that provide inaccurate info about opening hours.

Good luck!

esmadrid.com has a nice write up about Madrid on a Monday. I assume Barcelona and Sevilla also have something similar

https://www.esmadrid.com/en/monday-madrid

You have got answers on TA too.

thanks. i did also post on ta...gotta say i get different answers to different questions in both of these forums. am loving the specificity here on fodors.

Whether you are or are not a Rick Steves fan, one of the things I like about his books (and I expect might be on his website) is the short list of open and closed days for the key sites in relevant cities. Of course it pays to double check, but that allows me to get some sort of city itinerary going. I remember Istanbul being particularly challenging when I was there on a Sunday, Monday, Tuesday. His short list gave me some perspective of what I could fit in and when.