Nimbus Isle is the medium Nimbus Stationproperty. It was released in the May patch in 2011, and the launchpad is by the water's edge in Brick Annex, directly next to Rad Eccles. Its launchpad is, in fact, in the same spot the Frostburgh launchpad used to be at. The Property Guard is Bud Nippit. In a message boards post, Imaginatrix said "The Nimbus Isle Prop is [about] the same size as the Avant Grove Property. Though the layout is a bit different - it's square for once" meaning more usable building space as opposed to some of the other, rounder, properties, although the height limit on Nimbus Isle is significantly lower compared to Avant Grove.
Nimbus Isle is be the first property surrounded by water to be released. There were some other properties (Pirate's Cove and Lagoon) containing water that were accessible in Alpha testing, but they were never officially released.
It is said that Nimbus Isle is the same size as Avant Grove, however it is notably bigger.