Have your favourite pet blessed, visit an underground mine in the centre of Madrid, see the astounding liquefaction of the blood of Saint Pantaleon once a year, meet Spain's only Catholic exorcist, find out how the king had his medicine made using alchemy, smell the apple odour that wafts once a year from the still-intact body of Mariana de Jesus who died in the 17th century, visit an underground art gallery, dine in a car park... Madrid is overflowing with extraordinary and little-known places and curiosities. You just have to know where to look... An essential guide for those who think they know Madrid well or for those looking to discover the hidden side of the city.