Nippara Limestone Cave

Sure, it’s way out in the middle of nowhere, a two-hour trip from Shinjuku, but this eerie limestone cavern is perfect for escaping Tokyo’s suffocating summer heat: the temperature inside is a steady 11 degrees Celsius. Around 800m deep, the caves were formed over millions of years and were once a centre for Japanese mountain cults – fittingly enough for an otherworldly realm far removed from the sleepy countryside up above. The paths inside the cave are well lit and clearly marked but often wet, so make sure to wear sturdy shoes. Bringing your own bento is also recommended as there are hardly any eateries in the area.