La Piedad Roadside Chapel, in Pasai Donibane, has a rectangular ground plan bordered by three ashlar stone walls and a gable roof creating a pediment. The front consists of two stone columns with a cylindrical shaft and beautiful Mannerist capitals. Between the columns is a simple iron railing and, in its interior, an altar, over which there is an image comprising a cross and image of Our Lady of Mercy. This roadside chapel could be considered as popular Renaissance in style.
Formerly perforated in the same rock, this chapel was initially nothing but a stone cross with a Latin inscription engraved in the rock serving as its base. The cross dated from the 15th Century and had was typically decorated with studs.
When plans were made to enlarge it in 1580, the rock with its inscription had to be disposed of. Having completed the work, the original cross stood on a stone altar and the inscription, translated into Spanish, was carved on either side and on the iron plaque commemorating the Battle of Roncesvalles at which the Vascones defeated the troops of Charlemagne.
The image of Our Lady of Mercy, carved on the cross, permitted crews from ships mooring in front of it to take mass as far back as the 17th Century.
Ever since far-off times, somewhere around the 16th Century, the people of Pasaia have been holding a commemorative celebration to the sound of the typical local instruments: the txistu flute and tamboril drum.