At least, it is generally assumed to be the family’s memorial.
Known locally as the Killigrew Monument, it was erected on the orders of one Martin Lister (d.1745), a soldier who had married into the Killigrew family – and who’d had to change his name to Lister-Killigrew in order to benefit from his wife’s inheritance, his wife Anne being the daughter of Sir Peter Killigrew (d. 1705) and, as they had no children, the last of the line. After his wife’s death in 1727, Lister-Killigrew left Falmouth but later sent instructions to his steward at Arwenack that the stone pyramid be built. These instructions were apparently quite detailed but its exact purpose is unclear as Lister-Killigrew was adamant that there should be no inscription. Apparently he never saw it completed as he never returned to Falmouth.
Standing some 44 feet high, the lack of inscription means that the Killigrew Monument is something of a mystery although it is generally assumed to have been intended as a memorial to the family who founded the town of Falmouth in the seventeenth century. It has been moved a couple of times since being erected, and has been at its current location since 1871. Local legend has it that during one of the previous relocations, two wax-sealed glass bottles were found underneath it. Accounts of this vary – some say the bottles were filled with parchment or coins, while others say they were empty (which sounds unlikely).
One of the more fanciful stories is that the pyramid is in some way a means in indicating the location of buried treasure, for there has been more than one story about the Killigrews of Arwenack being involved in nefarious activities, from smuggling and receiving stolen goods to piracy and murder. One of them, Mary Killigrew, who lived in the sixteenth century (the actual years of her birth and death are unknown), was actually convicted of piracy and sentenced to death although she was pardoned by Elizabeth I. She had sent her servants to raid a Spanish ship that had sought shelter in Carrick Roads (one of the largest natural harbours in the world and the reason for Falmouth’s existence), and she is reckoned to have buried some of her ill-gotten gains in the grounds of Arwenack House.
So could the Killigrew pyramid be a way of indicating where Mary Killigrew’s treasure might be buried? It sounds unlikely, but as Martin Lister-Killigrew didn’t say why he wanted the monument to be built, we’ve no way of knowing for sure.