The Osaka Loop Line is a railway loop line in Japan operated by the West Japan Railway Company. It encircles central Osaka.
A 323 series train on the Osaka Loop Line in September 2017
103 series (left) and 201 series EMUs
A circle route is a public transport route following a path approximating a circle or at least a closed curve.
High Street Kensington station on the Inner Circle line in London, the world's first circle line.
Line 10 of the Beijing Subway, the world's second longest circular metro line