It was issued as a limited edition vinyl LP by Kevyt Nostalgia/Super Metsä in 2004. It is a recording of a concert from 9 October 2004 at Holy Trinity Church, Leeds, United Kingdom. Circle headlined the bill, which also included Guapo. (Guapo's Daniel O'Sullivan and Circle's Jussi Lehtisalo have collaborated in Grumbling Fur.) The set comprised one long improvised piece, dominated by Mika Rättö's electric piano and Janne Westerlund's acoustic guitar. For the album release, the track was named "Diamond" and split into two parts on either side of the LP.
Mountain is one of a series of vinyl-only albums released by Circle which document their often improvised freeform live shows.