León is the largest city on the Pilgrimage of Santiago de Compostela apart from Santiago itself, boasting many notable architectural buildings, and has a history going back as far as the 1st century BC. The most famous building today would be the Gothic Cathedral which took the full 13th century to complete, with further additions made later, and is especially noted for having a large proportion of stained glass windows. Gaudi's Casa de Botines is also a landmark building, boasting unique towers at each corner.
The two main markets are:
1. The food market; Wed & Sat mornings in the Plaza Mayor, where you can find lots of fresh fruit and vegetables and dried meat and local cheese from the butchers and cheese-mongers themselves.
2. The clothing and accessories market on a Sun morning along the river bank (not far from the train and bus stations; just over the bridge).
León is one of the few places left in Spain that still offers free tapas with your drink, each bar serves a different dish so it is custom to move from bar to bar trying out all sorts of typical foods. There is a concentration of these "tapas bars" in the "Barrio Húmedo" section of the city center, although they are not exclusive to this area.
Later on at night there are many options for the night-owl in the line of clubs, parties and late night bars, and once one closes, another opens, so you can party til 10am if you wish!