Much of Jerusalem is covered in a web of ancient history, theology and philosophy. But outside the city along the banks of the Soreq creek, parts of a forest are literally covered by webs, spun by spiders.

Massive webs spun by long-jawed spiders—known as Tetragnatha—envelop sections of vegetation along the banks of the creek, which consists largely of treated sewage.

The waste material provides an abundance of nutrients for mosquitoes, which breed along the creek’s banks. And that’s good news for the spiders, since mosquitoes are their preferred food source.

The spiders then reproduce vociferously and the results are the incredible cobwebs outside the Israeli city, on a scale that is rarely seen elsewhere in the Middle East.

Igor Armicach, a doctoral student at Hebrew University’s Arachnid Collection, told Reuters that millions of the spiders contributed to the phenomenon. “It’s an exceptional case,” he said.

But for those keen to see the apparently enchanted forest, you’d better act fast. The forthcoming cold of winter will cause a dip in the mosquito population, leaving the spiders without a reliable source of food.