You're obliged to end up at the Cavern Club, a not-completely-uncharming replica of the vaulted, subterranean bar where the pre-Fab Four honed their fabulousness.
A 7 a.m. shift boss, Ryan McGinty, had recently come up from the cavern and was sitting on a stool at Daisy's Cafe, near the corner of 72nd and Second one afternoon, still wearing his hard hat when an explosion shook the restaurant.
Wainman has also created a model of the Beatles' early stage set-up at The Cavern club.
A few days later a Rio newspaper published an interview with the Portuguese novelist José Saramago, winner of the Nobel Prize in Literature in 1999, in which he confessed that he had been so moved by a visit to the museum that it ended up inspiring his latest novel, "The Cavern".
While in Tulum it is also worth swimming in any of the local cenotes - fresh water sink holes that make up the largest network of caverns in the world.
Cheered by a joyous crowd, and chronicled by television crews perched on rickety platforms in an impromptu tent village which became known as Camp Hope, a group of 33 miners now known across the world as "Los 33" were lifted to freedom, one by one, up a tiny shaft from the cavern where they had been trapped by a rock-fall 69 days earlier.
The name Grey Area refers to "the undefined space between art and design," in the words of the gallery's founders, Kyle DeWoody and Manish Vora, who teamed up with Cavern Wallpaper of Los Angeles to make the wallpaper available commercially.
Lexus has been giving celebrity-packed parties for its new LS model luxury car inside mini replicas of a 50-foot installation made of secondhand pine nailed into a free-form cavern, which lighted up the skyline at last summer's Burning Man.
In visibility of up to 60 metres, the caverns, drop-offs and jagged rocks of the Gozo coast make for a dramatic underwater landscape.
At the centre of the pit is a hole (black) that opens up into a cavern in the volcano.
