At the center , Piazza dei Signori is graced by Palladio 's first public work , the Basilica Palladina ( 1549 ) , not a church at all , but the old Roman concept of a gathering place for the lawcourts and assemby hall of the Gothic Palazzo della Ragione that it encases with a colonnade and loggia .
The Basilica Palladina is Palladio 's most famous church .