In the UK we have a useful website, geograph.org.uk, that allows you to put photos up under CCBY. But it takes a long time to tag, geolocate, title, and caption a photo.
Are there any similar sites where I can just post the photo with a quick caption, and make it available under a Creative Commons licence?
The answer will probably depend on where you, or the photo is.
You mentioned geograph.org.uk, which has always covered the UK and Ireland but if you go up a level to https://www.geograph.org/ you will see that it now covers Germany.
When it’s available again, you can also publish your photos under a Creative Commons licence on the Internet Archive (archive.org). There is no need to tag each individual photo in a single upload you can for example include several photos taken on a particular day or of a particular place. Like I’ve done here Internet Archive: Digital Library of Free & Borrowable Texts, Movies, Music & Wayback Machine. I’ve got over 20,000 photos on there now! The images are a bit more fiddly to browse than if they were uploaded and tagged individually, but I wouldn’t have had time to upload many images otherwise.
Note that at present it’s not possible to upload to the Internet Archive after the site was attacked recently, but it should hopefully be available again soon.
Just want to add that if you do end up publishing on the Internet Archive, donate some money to them. They provide a really important service - an increasingly important service - for all of us.