My visit to El Escorial was in November 2024 as a part of my nine months living in Madrid, Spain, and I have to say, El Escorial continues to stand out as one of my favorite sites in the country. The monastery is just massive and stunning beyond words... every time you think you've seen the final room, there is another one full of incredibly intricate, lavish detail sitting beyond the next doorway, and it continues on and on like this for hours. Frankly, a lot of the royal palaces in Spain are quite large and have a lot of distinct, highly decorated rooms, but El Escorial has them all beat. El Escorial was built both as a religious complex and a royal setting blended together. When we first arrived we were a bit peeved because the entry price + guided tour seemed to be pretty high. However, after having taken the tour and seeing the enormous size of the site, we now understand and think it's worth every cent.
My takeaway is that I cannot recommend El Escorial enough. Seemingly endless content to see, it's a great daytrip from Madrid. The biggest knock against it is perhaps that the town surrounding it does not have much to do other than a nice public park.
Some have said that there is a no-photography rule, and maybe that was the case in the past, but it is no longer true except for one specific room within the complex. (The masoleum that houses the bodies of generations of dead kings and queens.) Based on the way some of the other reviews on this site talk about El Escorial, I also wonder if more of the complex is open to the public tours now than was in the past. Also, to reaffirm Alikander99's warning, it is closed on Mondays! (We sent some friends there on a Monday by accident, not knowing this.)