Mount Inasa, Mountain summit in Nagasaki, Japan.

Mount Inasa is a 333-metre hill west of central Nagasaki, its slopes covered in dark green trees and its base packed with buildings and port structures. Near the crest stand tall red-and-white striped masts and a short grey cylindrical tower, transmitters serving Nagasaki's TV and FM stations. A multi-level observation deck with a rooftop platform sits a short walk from the ropeway and slope-car stations.

The summit's broadcast role began in the postwar era: analog TV transmitters for Nagasaki's stations started up and were joined by FM radio equipment. The analog services ended on 24 July 2011, and digital TV had launched on 1 December 2006. The ropeway opened in 1990, and the slope car, designed by Kiyoyuki Okuyama, began service in 2020.

The summit's night view is billed as the "10 Million Dollar Night View" and was named one of the World's New Three Great Night Views in 2012, alongside Monaco and Hong Kong. Local singer Masaharu Fukuyama's song "Promised Hill" is the official Mount Inasa song, and the park's outdoor stage has hosted his concerts and the Sky Jamboree festival.

The Nagasaki Ropeway runs 1.110 km from the base to the summit in a three-line shuttle system. Since April 2026 the slope car from the mid-level car park has been suspended long-term, so check the ropeway status before setting out. A 6,000-LED light tunnel links the ropeway station to the observation deck.

On clear days, visitors can see distant locations from the platform: the Goto Islands to the west, the Amakusa Islands to the south, and even Mount Unzen to the east. This expansive view makes any visit on good weather days particularly rewarding.