The Diocesan Shrine of San Isidro Labrador, generally known as Lucban Church, sits at the centre of the town's main plaza and is the focus of the Pahiyas Festival every 15 May. The thick stone walls and Baroque facade are typical of the Spanish colonial churches built across Luzon in the 18th century, but the size — three naves and a heavy bell tower — reflects Lucban's importance as the historic capital of the colonial province.
On festival day the church is the starting point for a procession of San Isidro through streets decorated with kiping (translucent rice-flour wafers in vivid greens, pinks, and yellows) and pyramids of fruit and vegetables. The rest of the year the building is a cool, quiet place to step into out of the midday heat. Mass times are posted at the entrance.