The Whistler Cork Oak (Sobreiro Assobiador)

A single stripping of this tree in 1991 produced more than 1,200 kilos of cork, reportedly enough to stopper over 100,000 bottles of wine. Most cork oaks do not manage that in a whole lifetime. This one has been harvested more than twenty times since around 1820 and is still working. It is called the Whistler for the noise. Songbirds gather in the crown at dusk and the sound carries down the street. Guinness lists it as the largest cork oak in the world, and in 2018 it won European Tree of the Year on 26,606 public votes, beating the ancient elms of Cabeza del Buey in Spain by a little over four thousand. It was planted in about 1783 or 1784, during the reign of Queen Maria I. The trunk measures 4.15 metres round at chest height and over six metres at the base, where a cork oak flares hard, and the crown spreads more than 30 metres. Its height is either 16.2 metres or 19 depending on which account you read, and nobody locally seems troubled by the gap. Portugal has classified it a Tree of Public Interest since 1988. In 2000 illegal building nearby came close enough to be a genuine threat, and the protection around it was tightened the year after. It stands in the open in Aguas de Moura, beside a playground and a row of benches, with a low fence round the trunk and people sitting in its shade most days.