A former haven of corsairs then of smugglers, from where
the Johnnies* set out to sell their pink onions, Roscoff is a small
seaside town which has preserved its architectural heritage from the 16th and 17th centuries. 
Built on the sea, the sacred perimeter contains the church, two ossuary chapels, one Gothic, the other Henry II style, and the funerary
monument of Dorothea Silburne, who welcomed, in London,
Monseigneur de la Marche, last bishop de Léon, emigrated in 1790.

The Renaissance bell tower, almost unique in Brittany, dates from 1575-1576.

*The Johnnies are onion growers and merchants from Roscoff and Santec who, from the 19th century to the middle of the 20th century, left, from July to December, to the United Kingdom, on the other side of the Channel, to sell their onions.