Gebooru.com in their own words is
Gelbooru is one of the largest hentai and safe image resource available! Over a million images for you to search and view, and it is all free!
Due to the nature of the website they are blocked by many countries, schools, etc. They have a very large collection of images and are often bookmarked in reddit.
Can you fix the bug where we can’t view images’ full size?