Every day, pedestrians in Murcia, Spain use the Manterola Bridge to cross over the Segura River and get to work, class, or other engagements.

Starting this week, though, they’ll have new commuting company. Thanks to a recently installed eel staircase, European eels traveling upstream will be passing right under their feet, Murcia Today reports.

Back in the 1990s, the Segura River was one of the most polluted in Europe, thanks to runoff from canning factories. By then, there was hardly any wildlife in the river. But over the past decade, as restoration efforts ramp up and the water becomes cleaner, many animals, including eels, are moving back in.

An artist's rendering of a European eel.
An artist’s rendering of a European eel. Felice Supino/Public Domain

Now, the eel population is large enough to justify its own infrastructure. This “eel staircase” or ladder is actually a ramp covered in artificial grass, which lets the eels wriggle over a small weir in the middle of the river and travel upstream. (European eels are usually born in the Sargasso Sea, and swim up inland rivers to live out their adult lives. They then return to the sea to spawn, restarting the cycle.)

“It is hoped that [the staircase] will enable eels to travel 15 kilometers further inland than is currently the case,” or about 9 miles, Murcia Today reports.

If it’s successful, the river will get at least one more eel staircase before the end of summer. Murcians, get ready for some buff eels.

Every day, we track down a fleeting wonder—something amazing that’s only happening right now. Have a tip for us? Tell us about it! Send your temporary miracles to cara@atlasobscura.com.