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Uranus has a faint ring system around the planet. William Herschel thought that he had discovered rings around the planet when he first spotted Uranus, but based on how faint they are, it seems unlikely that what he saw were the rings.
The rings are oriented parallel to the equator of Uranus and much like those of Jupiter and Saturn, are continually replenished by collisions by objects colliding with the moons of Uranus. They are very dark, though they contain icy particles because they are covered with dust from the moons and the lack of sunlight reaching the region around Uranus.
The rings themselves are very narrow, made up of meter-sized particles and smaller. The majority of the rings are no more than 10km wide, with the widest ring only 100km (less than 0.2% the diameter of Uranus). Much like Pandora and Prometheus keeping the F-Ring around Saturn narrow, the rings of Uranus are kept narrow because of shepherd satellites, like Cordelia and Ophelia maintain the ε-Ring (epsilon ring). The ε-Ring is actually very eccentric because of the highly eccentric orbits of Cordelia and Ophelia.
The ring around Uranus were first indirectly discovered in 1977 when Uranus occulted a star, i.e. passed in front of the star. Just before the disk of Uranus passed in front of the star, the star dimmed a little, and just after the Uranus passed in front, the star did not return to its original brightness. Based on the dimming, astronomers were able to conclude, correctly, that Uranus possibly had a ring system. It wasn't unitl Voyager 2 passed Uranus that we were able to image the rings directly, and show that Uranus did have rings.
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