Well, after a decade or so I've finally gone back to Aranjuez! here are my thoughts.

First off I think it's interesting noting that aranjuez was proposed fairly late among the Spanish sites and as a cultural landscape.

As many people have pointed out the actual highlight of the site are the gardens.

The palace is indeed kinda ghastly. The rooms were renovated in the 19th century when Spain, and particularly the crown, were in full crisis. The result is some interior design I wouldn't wish on my worst enemy. You can actually skip it tbh. 

The city itself is rather surprising, in the sense that I have no idea why Unesco actually allowed its inscription. A bit of context: Spanish royal sites were thought of as a retirement sites for the monarchs, so they had no population other than the people in charge of the palace and gardens. This changed with Charles III which built up towns associated to each royal site. Spain has for a long time tried to get Unesco to extend the site of El escurial to include the city of San Lorenzo, which was built during this period. Unesco "wasn't thrilled with the idea" . So imagine my surprise when I went back to aranjuez and found out that at large its city centre is in a comparable state. I mean the city and, particularly its plan, beautifully illustrates enlightened ideals of urban planning, but that's hardly unique in Europe. 

The actual star of the show as I pointed out before is the gardens, which imo could've included in the list alone, as superb examples of European royal gardens dating from the 16th to the 18th century.

 The sheer size of the trees is thoroughly impressive. The London plane trees rise to 50m. there's also a huge pecan tree, and some increadible ahuehuetes. In fact, this park shines through its variety of centenary northamerican trees. They adapted very well to the climate of aranjuez and have grown to inmense sizes. 

I wanted to take a second to zoom on the London plane, because it's a particularly interesting example. The tree in question is a hybrid between the western and Eastern plane trees, one found in northamerica and the other in central Asia. Its origins are debated but it's thought the hybridization probably happened in Spain or Southern France. And this kinda showcases the preeminent role Spain played in the introduction of American species into Europe. It's a part of history that's hard to represent in the list, as it was done before the rise of botany as a science and few Spanish gardens have survived the tellings of time (aranjuez might be the best, and no tree is actually older than 300 years). Anyway, the London plane tree has become one of the most common urban trees in the world, so having a site like aranjuez show the royal standing of the tree in the 18th century is kinda interesting, though alas the hybridization happened a few centuries earlier. 

All in all I think the gardens of aranjuez beautifully complement the site of El escurial and give you a rough idea of what the spanish monarchs searched for in a royal site. The only thing missing are the hunting grounds. 

As a final anecdote, I helped some townsfolk recollect nuts from a 200 year old pecan tree. Kind of nuts tbh