400-499
- 400: Kitami Observatory
- 401: Oosato
- 402: Dynic Astronomical Observatory
- 403: Kani
- 404: Yamamoto
- 405: Kamihoriguchi
- 406: Bibai
- 407: Kahoku
- 408: Nyukasa
- 409: Kiyose and Mizuho
- 410: Sengamine(Sengamine Observatory, Hyōgo, Japan)
- 411: Oizumi, Gunma, Japan
- 412: Iwaki
- 413: Siding Spring Observatory, Siding Spring, Australia
- 414: Mount Stromlo, Australia (Mount Stromlo Observatory)
- 415: Kambah, near Canberra, Australia (Kambah Observatory)
- 416: Barton, near Canberra, Australia
- 417: Yanagida Astronomical Observatory
- 418: Tamworth
- 419: Windsor
- 420: Sydney, Australia
- 421: Mt. Kajigamori, Otoyo, Australia
- 422: Loomberah
- 423: North Ryde
- 424: Macquarie, near Canberra, Australia
- 425: Taylor Range Observatory, Brisbane, Australia
- 426: Woomera, Australia
- 427: Stockport
- 428: Reedy Creek
- 429: Hawker
- 430: Rainbow Observatory, near Coonabarabran, Australia
- 431: Mt. Tarana Observatory, Bathurst
- 432: Boambee
- 433: Bagnall Beach Observatory
- 434: S. Benedetto Po
- 435: G. Colombo Astronomical Observatory, Padua
- 436: Osservatorio di Livergnano
- 437: Haverford
- 438: Smith College Observatory, Northampton, Massachusetts, USA
- 439: ROTSE-III, Los Alamos, New Mexico, USA
- 440: Elginfield Observatory, Ontario, Canada
- 441: Swilken Brae, St. Andrews
- 442: Gualba Observatory
- 443: Obs. Astronomico Plomer, Buenos Aires, Argentina
- 444: Star Cruiser Observatory, Anza, California, USA
- 445: Observatori d'Ontinyent
- 446: Kingsnake Observatory, Seguin, Texas, USA
- 447: Centennial Observatory
- 448: Desert Moon Observatory, Las Cruces, New Mexico, USA
- 449: Griffin Hunter Observatory, Bethune, South Carolina, USA
- 450: Carla Jane Observatory, Charlotte
- 451: West Skies Observatory, Mulvane, Kansas, USA
- 452: Big Cypress Observatory
- 453: Edwards Raven Observatory
- 454: Maryland Space Grant Consortium Observatory
- 455: CBA Concord
- 456: Daventry Observatory
- 457: Partizanske
- 458: Guadarrama Observatory
- 459: Smith River Observatory, Danbury
- 460: Area 52 Observatory, Nashville, Arkansas, USA
- 461: University of Szeged, Piszkéstető Stn. (Konkoly)
- 462: Mount Belleview Observatory
- 463: Sommers-Bausch Observatory, Boulder, Colorado, USA
- 464: Toby Point Observatory, Narragansett, Rhode Island, USA
- 465: Takapuna
- 466: Mount Molehill Observatory, Auckland, New Zealand
- 467: Auckland Observatory, Auckland, New Zealand (Stardome Observatory)
- 468: Astronomical Observatory, Campo Catino (Osservatorio Astronomico Campo Catino)
- 469: Courroux
- 470: Ceccano
- 471: Houstrup
- 472: Merlette
- 473: Remanzacco
- 474: Mount John Observatory, Lake Tekapo, New Zealand (Mount John University Observatory)
- 475: Turin Observatory (before 1913), Italy
- 476: Grange Observatory, Bussoleno, Italy
- 477: Galleywood
- 478: Lamalou-les-Bains
- 479: Sollies-Pont
- 480: Cockfield
- 481: Moorwarfen
- 482: St. Andrews
- 483: Carter Observatory, Black Birch Station
- 484: Happy Valley, Wellington
- 485: Carter Observatory, Wellington
- 486: Palmerston North
- 487: Macnairston Observatory
- 488: Newcastle upon Tyne
- 489: Hemingford Abbots
- 490: Wimborne Minster
- 491: Centro Astronómico de Yebes, Spain
- 492: Mickleover
- 493: Calar Alto Observatory
- 494: Stakenbridge
- 495: Altrincham
- 496: Bishopstoke
- 497: Ascot-Loudwater
- 498: Earls Barton
- 499: Cheam
Read more about this topic: List Of Observatory Codes