References

Wikipedia: Tokyo Page - Used for historical information and must-see spots in Tokyo.
Wikipedia: Kyoto Page - Used for historical information and must-see spots in Kyoto.
Wikipedia: Osaka Page - Used for historical information and must-see spots in Osaka.
Wikipedia: Hiroshima Page - Used for historical information and must-see spots in Hiroshima.

Tokyo

Kinkaku-ji: Photo by Jaycangel, CC BY-SA 3.0, via Wikimedia Commons
Fushimi Inari Shrine: Photo by Basile Morin, CC BY-SA 4.0, via Wikimedia Commons
Kiyomizu-dera: Photo by Jordy Meow, CC BY-SA 3.0, via Wikimedia Commons
Gion: Photo by 663highland, CC BY-SA 3.0, via Wikimedia Commons
Arashiyama Bamboo Grove: Photo by Basile Morin, CC BY-SA 4.0, via Wikimedia Commons
Ryoan-ji: Photo by Cquest, CC BY-SA 2.5, via Wikimedia Commons

Hiroshima Memorial: Photo by Balon Greyjoy, CC0, via Wikimedia Commons
Shukkei-en Garden: Photo by Fg2, Public domain, via Wikimedia Commons
Miyajima Island: Photo by Bernard Gagnon, CC BY-SA 3.0
Hiroshima Castle: Photo by DXR, CC BY-SA 4.0, via Wikimedia Commons
Museum of Art: Photo by Taisyo at Japanese Wikipedia, CC BY 3.0, via Wikimedia Commons
Peace Boulevard: Photo by Atabəy, Public domain, via Wikimedia Commons
Okonomi-mura: Photo by Taisyo, CC BY 3.0, via Wikimedia Commons

Osaka Castle: Photo by 663highland, CC BY-SA 3.0, via Wikimedia Commons
Dotonbori: Photo by Martin Falbisoner, CC BY-SA 4.0, via Wikimedia Commons
Shitennoji Temple: Photo by 663highland, CC BY-SA 3.0, via Wikimedia Commons
Umeda Sky Building: Photo by Kakidai, CC BY-SA 4.0, via Wikimedia Commons
Universal Studios Japan: Photo by Unknown, CC BY-SA 3.0
Osaka Aquarium Kaiyukan: Photo by Teddy Yoshida, Public domain, via Wikimedia Commons
Minami (Namba): Photo by Kirakirameister, CC BY-SA 3.0, via Wikimedia Commons