They appear on Venus, in certain areas on Mars, in the Vault of Glass, and the Black Garden, teleporting reinforcements to battle Guardians and others. Skolas utilized several of these Gates during the House of Wolves' Story mission Queen's Ransom, where he attempted to pull his entire House through time and space.
In the Prison of Elders there is a single inactive gate similar to the one used to enter the Black Garden, which is where the boss of that round stands. Many Crucible maps, such as Vertigo and Crossroads, feature active Transfer Gates which teleport Guardians about the map.
List of appearances