New York Times: What's going on in this Picture?
Intriguing Times images stripped of their captions — and an invitation to students to discuss them live.
Multipilicity Lab: What do you notice? What do you wonder?

Multiplicity lab was founded at Northwestern University’s School of Education and Social Policy to support the teaching of mathematics but provides high-interest images that students in all disciplines would be excited to discuss.
Learner.org Photographs

A collection of photographs tied to environmental, global, products and practices
Unsplash Images

Free images related to daily life, nature, and cities. All images can be downloaded and used for personal or commercial projects.
Once Upon a Picture
A resource for imaginative illustrations to get students making inferences and narrating.
Historical Photos
A collection of historical photos. Students can try to guess what is going on and will be amazed when the answer is revealed! Most of which come from the following source:
https://www.facebook.com/theworldchronology?mibextid=ZbWKwL
Spot the Difference Pictures
High quality picture puzzles that will test how observant students are as they try to spot the differences between two images that look nearly identical. For each puzzle, there are five differences between the pair of pictures.
Conversations
A collection of conversational photos for students to "fill in" the dialogue, discuss the situation, role-play and much more!
NPPA Best of Photojournalism
This site displays the photojournalism winning photos for each year, having won for various categories. These photos truly tell a story and inspire lots of discussion. Warning: some images depict intense (and potentially disturbing) events from around the world; teacher discretion is advised.
Drone Videos
This site has a wonderful collection of drone videos from Argentina, Colombia, Chile, Perú, Venezuela, Ecuador, Bolivia, and Uruguay. This is a great way to get students to narrate what they see, make observations or comparisons with their own city or between two of these cities.
Visuals for Foreign Language Instruction
This site from the University of Pittsburgh contains hundreds of illustrations that can be used to support student communication such as describing objects, people, events or situations while teaching vocabulary or grammar. Simple black and white images are easy to incorporate into a lesson.
Image Generator
Along with many suggestions of writing exercises and ways to have students use and write about different images, there are several really wonderful and high-quality images provided.