What is the best time to visit Zaragoza? I'd would say Spring and Autumn.
The climate is extreme there, purely continental. During summer 40 Celsius or more is the norm, in Winter you get frozen, and it's ALWAYS windy (good point, probably the less polluted city of Spain!).
There are very interesting Easter traditions, even not so well knows as others in Spain (as many things on this city). So Semana Santa is a good time to visit, and see a few impressive processions accompanied by the traditional Aragonese drums.
And... of course, El Pilar (October 12th). Around this date the city celebrates a big festival, during a few days. Street music and parties, parades... and finally the famous offer of millions of flowers to the Virgin. You'll see lots of local people proudly wearing their traditonal costumes.
If you are a Catholic, the place that Zaragoza is absolutely well-known for is the Basilica of Our Lady of the Pilar. She is the Patroness of Spain. This basilica is absolutely impressive. Its huge and inside it houses this really dainty little statue of the Virgin Mary.
Fondest memory: I was in Zaragoza in October for the feast of Our Lady of Pilar. I have never seen so many people in native Aragon costumes. It was a sight to behold. Thousands of men, women, and children went to the square right beside the Basilica with offerings of flowers and produce to be given to Our Lady of the Pilar. One has to simply marvel the faith of these people!
Favorite thing: If you want to bring up to date buy the local newspaper ' El Heraldo de Aragón ', you ´ll find all the museums, all the movies in cinema ... and of course all the local and spanish news.
If you come to this pleasant city (not in winter) you must see the typical sites (museums churches etc ...)
but it is advisable to visit the 'tubo', a maze of streets in the heart of the town and you can find little shops, beautiful houses and good bars with good drinks.
Favorite thing: Plaza del Pilar Most of Zaragoza's main sights are grouped in this square including the town hall,The Basilica de Nuestra de Senora del Pilar and La Seo. This cool fountain is also there.
Visit El Pilar and La Seo two cathedrals in the same square, and don't forget the Aljaferia because is the most important building in mudejar style (melange of roman and arabic style).
Fondest memory: Like me, you will miss the quiet life of a spanish medium city. There is not stress in my city althought we are 700.000 people living in.
Indiscutiblemente lo más importante desde el punto de vista turístico es la Basílica en la que se venera a Nuestra Señora del Pilar a la orilla del Río Ebro
Fondest memory: La majestuosa Iglesia dedicada a la Sma. 'Pilarica'
Favorite thing: Spain has been repeatedly won. Then Spain has won the half-world. This globe symbolizes the Spanish sea gains.
Favorite thing: There is a natural park well prepared for tourism called ORDESA. But the other hillside of the same mountain is also beautiful and more 'wild'. I prefer this one and it is called PINETA.
Favorite thing: Travel to the Pyrenees (around 100 km from Zaragoza, driving to Huesca). AINSA is an old small town with and old and beautiful square and an old tower from where you can see the merge of 2 rivers.