The Sky Ramp was a monumental elevated road built on Onderon, and the only route to the battlements of the high walls surrounding the Royal Palace of Iziz. Rising out of the Merchant Quarter's starport, the Sky Ramp rose over the city and terminated at the Royal Palace's front gates. Having played an important defensive role throughout the Beast Wars and Mandalorian Wars, during the Onderon Civil War, towards the end of the First Jedi Purge, the Sky Ramp was the site of a skirmish that determined the outcome of the Onderon Civil War.
The Sky Ramp was constructed as a series of multi-level open-air passageways, merging into a single elevated road, that served as the only route to reach the battlements of the high walls protecting the city of Iziz from the wilderness of Onderon. One of the secondary ramps, located in the Merchant Quarter, led directly to the Royal Palace, and as of the year 3951 BBY, was heavily defended by many forms of defensive measures.
At the entrance to the Palace Sky Ramp, a steep incline lead to a small plaza that was the site of an air defense tower equipped with turbolaser turrets, and a military barrack housing Onderonian soldiers and officers; the soldiers and officers had postings at select intervals along the Ramp, with a small group on permanent duty at the entry gate. A second walkway, leading to the courtyard of the Palace at the summit of the Ramp, was protected by two force shield checkpoints; both of which could be disabled through security terminals in the nearby barracks, or by either a lightsaber or an energy-arm.
An Air Defense Tower on the Sky Ramp.
As a structure built for the purpose of protecting Iziz and the Royal Palace, the Sky Ramp has played an important role in the battles that were fought on Onderon. Throughout the Beast Wars, the AD Tower was crucial against Drexl-mounted Beast Riders and again during the Mandalorian Wars, in a vain attempt to stop the Basilisk war droids. However, during the Onderon Civil War, towards the end of the First Jedi Purge, the ramp leading to the Royal Palace was the location of an initiatory conflict that determined the outcome of the Civil War.
By 3951 BBY, at the culminating point of the Civil War, General Vaklu's separatists, bolstered by the Sith Triumvirate, had wrested control of the Sky Ramp away from Queen Talia's royalists; the force field checkpoints and the AD Tower came under the authority of Vaklu soldiers, which included Sith forces and boma beasts. Jedi Knight Meetra Surik and two of her companions, guided by the royalist Captain Bostuco, arrived soon after and the group made their way through the rear guard of Vaklu's minions, releasing Onderonian royalists trapped in the barracks and taking control of the Air Defense Tower; using the security terminal in the tower, Surik was able to eliminate six of General Vaklu's bombers and deactivate the first force shield checkpoint. Anxious to press the advantage, Surik and the royalists under her lead, fought their way to the entrance of the Royal Palace, continuously harassed by power conductors exploding under the direction of an expert slicer hired by Vaklu. After the Sky Ramp was cleared from Vaklu's soldiers and Sith reinforcements, Meetra Surik, her companions, and the royalists left to continue the battle inside the Palace.
Some time following the conclusion of the Civil War, the Sky Ramp and the Royal Palace were removed and the Unifar Temple was erected in its place. Where the Sky Ramp once rose out of the Merchant Quarter, Yolahn Square was built and served as a public assembly area below the stairs of the palace.
Vaklu's bombers being gunned down.
The sequence of events during the battle depends of the Jedi Exile's loyalty. Should she have sided with General Vaklu, she would have led the initial assault of the separatists, facing the Sky Ramp's complete arsenal. The power conductors would be used against the Exile, the slicer being hired by whoever she does not side with.
In game dialog, the Exile says "Guarding the Sky Ramps will be very important." However, as this is the only time in the game where the plural form is used to name the Sky Ramp, it is likely a mistake.