Local Secret · Osawa / Mitaka

National Astronomical Observatory of Japan, Mitaka 国立天文台 三鷹キャンパス

Japan's national observatory opens part of its leafy Mitaka campus to visitors every day for free. You can walk among 1920s domes, see the country's largest refracting telescope, a 65 cm giant from 1929, and follow a scaled-down Solar System walk through the woods.

About

The observatory moved here from Azabu in 1924, and its campus is a peaceful forest dotted with historic observation domes. The visitor route is free and self-guided after you sign in at the main gate. The highlight is the Astronomical History Museum, a 1926 dome housing the 65 cm refractor that was the largest of its kind in Japan and stayed in use until 1998. You can view it from a gallery. Nearby are the 1921 First Equatorial Telescope Dome, the oldest building on site, the Einstein Tower used for solar research, and a Solar System walk at 1:14-billion scale. The observatory also runs the 4D2U dome theatre and regular stargazing nights by advance booking. It's free, quiet and fascinating, and many Tokyoites have never heard of it.

Highlights

• A 65 cm refracting telescope from 1929 in a historic dome
• The 1921 First Equatorial Telescope Dome, a registered cultural property
• The Einstein Tower solar observatory
• A scaled Solar System walk through the campus woods
• Free entry, with the 4D2U dome theatre and stargazing nights by reservation

Tips

• Sign in at the guard post at the main gate and wear the visitor sticker.
• Book 4D2U dome theatre showings and the regular stargazing nights in advance on the official site.
• Take the Odakyu or Keio bus from Mitaka, Musashi-Sakai or Chofu to Tenmondai-mae.
• Combine with Jindaiji temple and soba, about 20 minutes' walk south.

Open in Google Maps · Info checked 2026-10-09

Nearby

• Nogawa ParkPark · 1.2 km away
• Jindai Botanical GardensGarden · 1.4 km away
• Jindaiji Temple & Soba VillageTemple · 1.7 km away
• Fuda Tenjin-shaShrine · 2.5 km away
• Tenjin-dori Kitaro Street (Chofu)Shopping Street · 2.6 km away
• Musashino ParkPark · 2.7 km away
• Hake no Michi & Hake no Mori MuseumLocal Secret · 2.9 km away
• Sengenyama ParkPark · 3.2 km away