The view from de Young Tower, San Francisco, by Instagrammer @holidayhaus.

Cities are a hot topic at the moment. As more and more of the world’s population gravitates toward living in them, people from all professions are coming together to figure out how to create infrastructures and environments to suit human needs and desires in the 21st century. These are huge issues, and you can be sure that the conversation, discussion and outright disagreement on how best to proceed will continue. Including at our own TEDCity 2.0 Day, taking place on September 20.

But cities are also exciting, vibrant and interesting places because of each resident’s experiences within them. After all, these smaller moments and movements coalesce to characterize the indefinable — the spirit and soul of a modern-day metropolis. So we’re launching a series of Instagram-based photo challenges, to collect and celebrate individual views and visions of cities the world over. This weekend, we want to look at the view of your skyline. Whether you live in a metropolis full of skyscrapers or a small community by the ocean, whether you’re a high-flying city official or a worker bee, we want to see what you see.

The challenge runs over on Instagram, so post your pictures there and use the hashtag #citiesdiscovered so we can find them. We’ll regram a selection of our favorite images — and post them here too. Also watch out for further photo challenges, coming soon.