People working at a dairy farm in Rotorua, New Zealand woke up one morning last week to the ‘biggest ever’ sinkhole revealing a volcanic rock that, according to scientists, is 60,000 years old.

Geologists are excited and thrilled at the same time about the appearance of the enormous sinkhole that appeared a few days ago in New Zealand, as it offers them the chance to study an ancient volcano. The crater is only 15 kilometers (abound 9 miles) away from the city of Rotorua and its measures are immense: about 200 meters long (650 ft) and 20 meters (65 ft) deep, as well as 20 m wide in some places. This is the equivalent of two football fields in length and a six-story building in depth. The hole appeared after it rained heavily for several days in a row.

According to GeoNet, which is a project of the Earthquake Commission in New Zealand, this type of collapse craters are not something new in this region. It is known that the region presents volcanic faults beneath and that there’s also the crater of an ancient volcano, which erupted more than 60,000 years ago. For this reason, the soils here are pumice-strewn and soft whenever it is pouring rain in the region, such sinkholes develop.

Colin Tremain, the owner of the farm in the region where this immense crater appeared said that he has plans to “put a fence around it” in order to avoid livestock to fall into the hole and to “forget about it”.

“We’ll keep it fenced off as it is to keep stock out, although stock aren’t stupid, they’re not going to walk into a hole, they can spot danger,” were his words in an interview he gave to ABC News.

Over the weekend, scientists have recorded the highest hourly rainfall and estimated that nearly 52 millimeters of water fell over just one hour last Sunday. According to them, this is the amount of water to fall in an entire month.

Authorities estimate it will take a few months until the town gets back on its feet after these heavy rainfalls.