1. search the image logo on the left and find out it is Asahi Broadcasting Corporation Television
2. notice the quality of the photo and search for old osaka expo
3. found the osaka 1970 and searched on the website circular buildings [link](https://www.asahi.co.jp/expo70_archive/)
4. found and tried this [link](https://www.asahi.co.jp/expo70_archive/?link=165)

Original writeup (https://github.com/juke-33/Write-ups/tree/main/Full%20Week%20Engineer%20CTF%202025).