300-399
- 300: Bisei Spaceguard Center - BATTeRS, Okayama, Japan
- 301: Mont Mégantic, Québec, Canada (Observatoire du Mont Mégantic)
- 302: University of the Andes station, Venezuela (not built)
- 303: Mérida, Venezuela (Llano del Hato National Astronomical Observatory
- 304: Las Campanas Observatory, Chile
- 305: Purple Mountain, Hainan Island station
- 306: Observatorio Taya Beixo, Barquisimeto
- 309: Cerro Paranal, Chile (Paranal Observatory)
- 312: Tsingtao field station, Xisha Islands
- 318: Quinns Rock
- 319: Perth Observatory, Perth-Lowell Telescope
- 320: Chiro Observatory
- 321: Craigie
- 322: Perth Observatory, Bickley-MCT
- 323: Perth Observatory, Bickley
- 324: Peking Observatory, Shaho Station
- 327: Peking Observatory, Xinglong Station (Xinglong Station (NAOC))
- 330: Purple Mountain Observatory, Nanking
- 333: Desert Eagle Observatory, Arizona, USA
- 334: Tsingtao
- 337: Sheshan, formerly Zô-Sé
- 340: Toyonaka
- 341: Akashina
- 342: Shishikui
- 343: Younchun
- 344: Bohyunsan Optical Astronomy Observatory (BOAO)
- 345: Sobaeksan Optical Astronomy Observatory
- 346: KNUE Astronomical Observatory
- 347: Utsunomiya-Imaizumi
- 348: Ayabe
- 349: Ageo
- 350: Kurohone
- 351: Sakamoto
- 352: Konan
- 353: Nishi Kobe
- 354: Kawachi
- 355: Hadano
- 356: Kogota
- 357: Shimotsuma
- 358: Nanyo
- 359: Wakayama
- 360: Kuma Kogen, Ehime, Japan
- 361: Sumoto
- 362: Ray Observatory
- 363: Yamada
- 364: YCPM Kagoshima Station
- 365: Uto Observatory
- 366: Miyasaka Observatory
- 367: Yatsuka
- 368: Ochiai
- 369: Chichibu
- 370: Kochi
- 371: Tokyo-Okayama (Okayama Astrophysical Observatory of Tokyo Observatory) (OAO)
- 372: Geisei Observatory
- 373: Oishi
- 374: Minami-Oda Observatory
- 375: Uzurano
- 376: Uenohara
- 377: Kwasan Observatory, Kyoto University, Kyoto (Kwasan and Hida Observatories)
- 378: Murou
- 379: Hamamatsu-Yuto
- 380: Ishiki
- 381: Tokyo-Kiso (Kiso Observatory, University of Tokyo, Nagano)
- 382: Tokyo-Norikura (Norikura Observatory of Tokyo Astronomical Observatory)
- 383: Chirorin
- 384: Shimada
- 385: Nihondaira Observatory
- 386: Yatsugatake-Kobuchizawa
- 387: Tokyo-Dodaira (Dodaira Observatory of Tokyo Astronomical Observatory)
- 388: Tokyo-Mitaka (National Astronomical Observatory, Mitaka, Tokyo)
- 389: Tokyo (before 1938) (Tokyo Astronomical Observatory)
- 390: Utsunomiya
- 391: Sendai Observatory, Ayashi Station
- 392: JCPM Sapporo Station
- 393: JCPM Sakura Station
- 394: JCPM Hamatonbetsu Station
- 395: Tokyo-Asahikawa
- 396: Asahikawa
- 397: Sapporo Science Center, Hokkaido, Japan
- 398: Nagatoro
- 399: Kushiro
Read more about this topic: List Of Observatory Codes