The Guggenhiem Museum in Bilbao. But really it's like asking the most famous thing in the USA - is it the Rockies, is it the Statue of Liberty, is is the War of Independence (called the Revolutionary War by Americans)?
Museo del Prado is the most famous of the lot which are there in Spain.
The Prado Museum in Madrid is probably the most famous attraction in Spain.
Although you might thing that Spain would have something like bull fighting for a famous sport they are renowned for there football/soccer. :)
Ferrán Adrià is the most famous chef in Spain he makes the delicous food in the world
bull
Madrid
Alhambra
Paella
Christopher Columbus
The aqueduct of Segovia.
spain
the most famous thing that Roberto clemente did was to collect 3,000 hits