This culvert is found in Radcliffe near Bury, it's about 260m long and outfalls into the Irwell.
This drain looks to have been built in the last few years. The whole system is concrete and there has been some major landscaping above ground. The dig a hole, fill it with prefab bits and scrape the earth back over method seems to have prevailed here.
I walked in from the outfall and found a large brick arch, the sides were scattered with stone debris with the river flowing sedately inbetween.
I came across this quaint little tunnel whilst scouring the banks of the Irwell. It looks to have been blasted into the local sandstone and finished in pick.
Sheffield was the final destination on my draining roadtrip with TheVicar, it was certainly saving the biggest till last. We went in via Porter's brook, the watercourse flows through nice old but stoopy culverts and open sections before converging with the River Sheaf.
The culvert had the same basic mushroom shape as Monument and afterwards I find it difficult to remember where one ends and the other begins.