KASUKABE, Saitama Prefecture--Visitors now have three options to explore an underground flood control facility here, a site so cavernous that one of its vertical shafts can hold the Statue of Liberty.

Two guided tours were added for the Metropolitan Area Outer Underground Discharge Channel, which started on March 23.

The discharge channel is a 6.3 kilometer-underground river built 50 meters deep to reduce flood damage. The main pressure-adjusting tank installed to collect rainwater is known as the “underground temple” for 59 colossal 18-meter-tall pillars.

The central government, which promotes infrastructure for tourism, conducted a pilot study of a tour planned and managed by a private entity for the first time last year.

A new 110-minute tour, costing 3,000 yen ($26.80), focuses on a vertical tank. In addition to the pressure-adjusting tank, participants can feel the scale of the 70-meter-deep cylindrical No. 1 vertical shaft.

The tour starts with a walk around the work aisle on the uppermost section, called the catwalk, to look down at the shaft. Visitors are allowed to take pictures on the stair landing about 100 steps down from the top.

The highlight of the other new tour, which lasts about 100 minutes and costs 2,500 yen, is the pumping chamber, the heart of the facility. It pumps up water into the Edogawa river.

Visitors can take a close look at the gas turbines consisting of jet engines used for aircraft.

The original tour is offered for groups for a fee of 1,000 yen each, allowing visitors to look down at the pressure-adjusting tank and the No. 1 vertical shaft.

Participants must be elementary school age or older.

For more information, visit the official website at (https://www.gaikaku.jp/).