The convicts' burial grounds
From 1776 until around 1817, the convicts were buried in unmarked graves inside the Warren. Great quantities of human bone were unearthed when the new gun factories were built in the late 1850s. Col Pilkington RE had complained to the War Office before 1817 about the "noxious and distressing" practice of burying convicts in ground that was already full to overflowing. It has been suggested that after 1817 burials took place on the north side of the river, however, this is unlikely. Pilkington investigated the possibility, but the Arsenal's holding of 13 acres on the north bank, used for grazing the Artillery's horses, was sold at auction soon after. It is more likely that the burial site moved to the far end of the Arsenal's land on the south bank, where it continued until the closure of the hulks in 1856. The following contemporary account is taken from "The criminal prisons of London" (Mayhew / Binney):-

The canal lock today looking north

"We now turned from the busy Arsenal, crossed the canal bridge, and approached the little black wooden lodge of the policeman who guards the gate leading to the marshes. Right before us is a vast earth work, all, as we are told, raised by convict labour! We approached it, and found the prisoners, with their brown jackets thrown off, and some with their legs buried in water boots, reaching to their thighs, digging the heavy, black, clayey soil and carrying it away in barrows under the eyes of two guards, with their cutlasses at their sides, and two NCOs of the Sappers and Miners, who were directing the works.

We turned away, and went further over the marshes, the ground giving way under our feet; and presently we passed behind the Butt, while the Minie balls were whistling through the air, and a solitary man was marking the hits. We approached a low piece of ground - in no way marked off from the rest of the marsh - in no way distinguishable from any section of the dreary expanse, save that the long rank grass had been turned in one place lately, and that there was an upset barrow lying not far off. We thought it was one of the dreariest spots we had ever seen. "This," said the governor, "is the convicts' burial ground". We could just trace the rough outline of disturbed ground at our feet. There was not even a number over the graves. The last, and it was only a month old, was disappearing. In a few months the rank grass will have closed over it, as over the story of its inmate.

The area in the 1850s

The contemporary engraving that accompanied the account

And it is, perhaps, well to leave the names of the unfortunate men, whose bones lie in the clay of this dreary marsh, unregistered and unknown. But the feeling with which we look upon its desolation is irrepressible. We followed the governor up the ridge that separates the marsh from the river and walked on, back towards the Arsenal. As we walked along we were told that under our feet dead men's bones lay closely packed; the ridge could no longer contain a body, and that was the reason why, during the last five or six years, the lower ground had been taken.

There is a legend - an old, old legend that has passed down to the present time - about a little pale-blue flower with its purple leaves, the Rubrum Lamium, which, it is said, grows only over the convict's grave - a flower tender and unobtrusive as the kindness for which the legend gives it credit. Botanists will of course ruthlessly destroy the local faith that has given this flower value, for they will tell you it is only a stunted form of the red dead-nettle."

The same scene today. The old marsh level is now covered by several metres of landfill.