The Monterey Cypress on the San Regolo Bastion

In the wild this species grows in two small groves on a single stretch of Californian coast near Monterey and nowhere else on earth. This one is twenty-eight metres tall and stands on the roof of a gun platform built between 1600 and 1605 by Piero Vignarelli, on walls that were designed to stop artillery and never had to. That is the joke of Lucca's fortifications: four and a half kilometres of state of the art sixteenth century defences that were never attacked, and which the city therefore turned into a park. Maria Luisa di Borbone laid out the promenade along the top in the 1820s, and from 1860 Cesare Bicchi, who ran the botanical garden immediately below the bastion, used the walls as an extension of his collection and planted exotic conifers where cannon had stood. This cypress is his, and at three and a half metres round it is one of only three trees on the whole circuit that the national register protects. It is evergreen, so it looks the same in February as in August, and it is free to visit at any hour, which the garden below it is not.