Tucked among boulders and bushes, an army-green cannon protruded from a hump of granite.
And small towns outfitted their village greens with cannons bought from the arsenal.
As if to highlight that, one of their first acts was to place a pair of green-oak cannons on the lawn, pointing directly out to sea.
Despite heavy rain, University officials held Class Day outside, so it was a sea of plastic orange ponchos and black umbrellas on Cannon Green behind Nassau Hall.
Yet the Flaming Lips respond in the only way they know how - with a prog-meets-garage extravaganza aligned to an eye-popping spectacle taking in glitter cannons, green lasers and balloons.
10.02pm BST O'Sullivan cuts a blue into the green pocket, but a cannon again denies him position, but he brilliantly cuts another red, then a blue, and gently bends round for another red.
Excellent - but then, in dispatching it into the middle, he cannons the green, prompting a further superb red.
The business of popular music will probably be split between tours involving whipped cream cannons and green vomit (KP, LG) and the coming world of no objects: the cloud that holds every song you own.
Built in the late 18th century by Sultan Sidi Mohammed Ben Abdullah (and designed by a French engineer he had captured), the town ramparts are in remarkable condition, with superb bronze cannons, some dark green with burnished patina and Portuguese crests; booty from long-ago wars.
Security troops in riot gear were out in large numbers, using rubber bullets, tear gas, water cannons filled with putrid green liquid and high-pitched noise machines.
