MADRID (BBC Travel) There are few grander public squares in Europe than Madrid’s Plaza Mayor, watched over on three sides by uniformly ochre-hued apartments with wrought-iron balconies, slate spires that dominated the city skyline in the 17th Century, and frescoes that turn golden at night on the square’s northern façade. First laid out in 1619, the plaza’s inauguration was auspicious. Its first public ceremony was the beatification of San Isidro, the patron saint of the city. But then in the 17th Century, supposed heretics were tried and executed here during the Spanish Inquisition -- burnings at the stake and deaths by garrotte took place on the north side of the square, hangings to the south. Later, the plaza hosted bullfights with 50,000 attendees, and royalty watched from their privileged balconies. Those same balconies became a negative focal point in 1673, when King Carlos II decreed that shopkeepers could raise tarpaulins above their stalls to fend off the raw sewage that the residents habitually tossed from the windows above. (Read the whole story, and more, on Madrid's Public Squares.