all photos by Christoffer Rudquist

If you’re looking for something fun and different to do in Tokyo this summer to escape the heat, consider Tokyo’s “Underground Temple.” But maybe plan your visit clear weather or you may find yourself evacuating.

Officially named The Metropolitan Area Outer Underground Discharge Channel, it’s the largest storm drain in the world. Completed in 2006, the anti-flood system lies 165 feet below Kasukabe City, is made up of a network of five silos connected by four miles of tunnels, and cost a reported $2 billion to construct. It’s a modern feat of engineering that’s out of sight and out of mind, but one day it may just save lives and prevent a whole lot of damage.

But when its 1400 horsepower turbine is not clearing 200 cubic meters of water every second, the city offers guided tours of the cavernous temple. Photographer Christoffer Rudquist ventured there last year and came back with these amazing photos that are as grand as they are dystopian.

Booking can be tricky though as the site is all in Japanese. And they require participants to either speak Japanese or bring a Japanese-speaking tour guide (details in English here). But for those who are able to score a spot to this exclusive underground exhibition will be in for quite a treat.