Here is a rare chance to bear witness to modern mountain-making: Shōwa Shin-zan (昭和新山; 398m) – whose name means 'the new mountain of the Shōwa period' – arose from a wheat field following the 1943 eruption of Usu-zan. The Usu-zan Ropeway runs up to a viewing platform for Shōwa Shin-zan, with Tōya-ko behind it.
From the observation deck a trail heads out on a 90-minute circuit (open May to October) around the outer rim of Usu-zan, with views of Tōya-ko and Yōtei-zan. Buses (one way/round trip ¥340/620, 10.10am, 12.45pm, 1.40pm and 3.50pm) run four times a day from the Tōya-ko Onsen bus terminal to the ropeway. A taxi should cost ¥1800; all the way from JR Tōya-ko Station, ¥3000.