Escuelas Pías de San Fernando

The walls you see on the south side of this square are what's left of a church that burned out in 1936 and then sat as a ruin for nearly seventy years, until a library was built inside it in 2004, with the rubble left where it lay.

From 1729 onwards this was home to the Colegio de San Fernando, run by the Piarists, a teaching order whose first school in Madrid stood right here, and in its best years it had more than two thousand pupils. During the Civil War the school and church were set alight and looted, and afterwards the site was carved up bit by bit between the covered market you just passed, a trade school, a block of flats and a cinema.

What the architect José Ignacio Linazasoro did between 2001 and 2004 was leave the ruin as a ruin. He set a new roof lower than the old drum, so from the outside the building stays a skeleton, and he let daylight in through wooden lattices that actually show off the scarred brick walls, a metre and a half thick.

You can look inside, though the window is narrow: on weekdays between a quarter past nine and ten, for no more than five people at a time, with larger groups by appointment.

At the end of the Calle de Tribulete we cross the Calle de Mesón de Paredes.