The larger of the two is circular and covered in wood whilst the smaller is just a simple slot in the wall.
These two holes are one of the few remaining vestiges of La Casa de la Misericòrdia - the House of Mercy, which was a religious institution run by nuns in the 19th century.
Until a generation ago, the wooden hole was a revolving door through which unmarried mothers anonymously abandoned their unwanted babies often under the shadow of night.
The small slot was where finanancial donations could be made to the nuns to help with the running of the hospice.
What is now local government administrative offices is actually part of a much larger collection of buildings many of which are still owned by the church and dedicated to charitable purposes.
The institution actually dates from 1581 when Diego Pérez de Valvidia, priest and Professor at the University of Barcelona, decided to found a small safe house for the homeless.
In only three years, the asylum was already known as the Hospital de Nostra Senyora de la Misericòrdia and a century later it finally became La Casa de la Misericòrdia, dedicated to helping donzellas necesitadas de amparo - damsels in need of shelter.
What few people who visit the OAC for some local administrative reason
realise is that most of the convents that made up the original Casa de
la Misericòrdia serve more or less the same purpose today.
The main entrance is now on Carrer de Elisabets 8-10 and the Casa de la Misericòrdia Foundation provides a home for minors from broken homes or families with serious economic problems.
The entrance used by most members of the public, however, is the OAC - Oficina d'Atenció al Ciutadà - Carrer de les Ramelleres, 17, where you need to go to do local paperwork, such as el padró.
Next time you go, make sure to have a look at the holes in the wall and notice that Casa d'Infants Orfes - House of Orphaned Infants - is written over the 17th century door.