Strange illuminated objects and artistic patterns of light are reflecting off the surfaces of Amsterdam’s canals and brightening the facades of nearby buildings as part of the annual Amsterdam Light Festival, which will remain in place until January 21st, 2018. This year’s theme is “existential,” challenging participating artists from 45 countries to produce light-centric artworks that envision some ways in which illumination could be used to bring people together. The installations interact with dozens of the city’s historic buildings, bridges, floating platforms, and ships. The result feels uniquely “Amsterdam,” adding a new dimension to the experience of exploring the city after dark.

The works are located along two exhibition routes: “Water Colors,” which follows the Amstel River around Amsterdam’s canal belt, and “Illuminade,” which is walkable. Boat tours are available from a variety of canal tour companies to take in Water Colors from the unique river perspective, while Illuminade is free and easy to access, featuring 20 light art installations within MarineTerrein Amsterdam, a new seaside development site within walking distance of Amsterdam Central Station.

This year’s exhibition even offers visitors the chance to catch a work of art by renowned Chinese artist Ai Weiwei. His contribution, “ThinLine,” consists of a four-mile-long fiberglass line that travels throughout the historical center of Amsterdam and lights up red during festival hours. Weiwei says his inspiration for the piece comes from the meaning of “boundaries.”

“The organization gave me a map of the area in which I was allowed to make a work, I copied that boundary, which has become my work. Define the border, and who can and can not cross it, and what’s inside and what’s not allowed.”

Other notable works include Balmond Studio’s “Infinita,” a duo of faceted quartz-like structures floating on the water, Ben Zamora’s “Myth,” consisting of vertical, horizontal, and diagonal lines lighting up on a grid, and VOUW’s “City Gazing,” a hovering light map of Amsterdam made entirely of LED lights on wires.

Lynne Leegte’s “Windows” projects the shape of two windows to represent the hidden Singel Baptist Church (which itself is set back from the street), illuminating a religious practice that was formerly seen as taboo in the liberal Calvinist nation.

“Whole Hole” by Paul Vendel and Sandra de Wolf turns the central opening under a bridge into an intriguing starburst that observers pass through on boat tours. “Homeward Bound” by Victor Engbers highlights the verticality of a ship with green and blue dots of light, and Driton Selmani’s “Eye to Eye” stands as an oversized talisman protecting Amsterdam from malicious gazes — whether they be mystical or more literal (like surveillance and other forms of privacy invasion) in nature.

“In the beginning of time, light existed in its most original form. Since the big bang, light has been a central force in the universe, a crucial factor in creating life,” explain the festival organizers. “Light is essential to our human existence, but we now regard it as a given fact. With the theme “Existential,” we go back to the earthly approach to light and make the existential properties visible and understandable again; the potential to shape, heat, vitalize, and connect. Light seems abstract but is in fact very tangible. By recognizing this, light forms inspiration for life itself.”

If you can’t make it to Amsterdam to see the installation in person, you can catch all of this year’s art at the Amsterdam Light Festival website.