Just as New Yorkers secretly love their sewer alligators, others have a place in their hearts for even the most disgusting of sewer oddities.  Fatbergs, in case you haven’t had the pleasure, are enormous, congealed lumps of cooking fat and other unmentionables that turn up in city sewers from time to time. Here’s one now:

Image: Rene Walter via Flickr, republished under Creative Commons

And, it turns out, they have groupies: yesterday, The Guardian reported that a British couple were such big fans of the UK’s largest, 15 tonne fatberg, that they took a trip to visit it. To celebrate.

Thames Water, amazingly, were happy for the pair to take the trip – they already had a BBC film crew plumbing the depths that day, so the couple, Dan MacIntyre and Dunya Kalantery, just tagged along. “It was unexpectedly pleasant down there,” MacIntyre told the paper.

“Then, says Kalantery, ‘we saw the fat, which was pretty great.’ Sadly, there were no giant clumps, thanks to the maintenance by sewer workers, but there was enough for the grease enthusiasts to get excited about. It was congealed around the pipes – the result of cooking fat and oil being poured down drains that solidifies around items such as wet wipes and sanitary towels that have been flushed (they shouldn’t be, but increasingly are), creating blockages. This causes sewage to back up, which can flood homes and streets.

“Was the fat as fascinating as she had hoped? ‘Yes, completely.’ She touched it, she smelled it (‘like solidified burnt oil’); she wanted to take some home as a souvenir, but it was impractical.”

The 15 tonne fatberg was lurking beneath the streets of Kingston-upon-Thames, where a family home will currently set you back somewhere in the region of £700,000. It was discovered by Thames Water workers in July 2014 and was, at the time, the size of a bus; unfortunately for fatberg fans, it’s since been removed, leaving nothing but some goo round the pipes.

Smaller fatbergs are apparently rife in the London sewer system, thanks to the nasty way cooking fat washed down sinks tends to congeal and harden as it cools. They require regular “flushing” by sewer workers to keep the pipes moving. In 2010, according to Londonist, “a team led by chief flusher Danny Brackley removed enough fat to fill nine double-decker buses, digging the stuff away from the walls using shovels”. 

You can read the rest of the Guardian’s (frankly, pretty brilliant) report on the official best anniversary ever here.