Helium is actually two cities commonly refered to as Greater and Lesser Helium. Greater Helium is larger and  has the mile- high scarlet tower which marks greater Helium from her twin city. Lesser Helium is the location of most of the museums of Helium and it's educational and scientific institutions. Greater Helium lies some seventy-five miles across the level plain from Lesser Helium. This plain is heavily cultivated and laid out in a striking checkerboard design. Each of the squares is a small family sized farm.
The incredably high slender Scarlet and Yellow towers line the wide streets and broad avenues and make a parklike canyon of the thoroughfares. Adding to the effect are flowers upon the scarlet sward of the strange red grass which lies about the buildings. From the sides of the towers you can see the carven balconies that the fortunate and wealthy have before their sleeping apartments.
One of the first things travellers notice about the city are the thousands of flyers that are constantly moving around the towers and occasionally darting high into the sky just for the joy of it. From a distance these look like gnats or mosquitoes, but they move too slowly for that. The city is designed around the needs of the flyers. Landing-towers are often found at the tops of the tall, thin towers of the twin cities of Helium as are lovely gardens. The numerous landing-stages are of all different sizes from the small personal or family flyer landings to the landing-stages that tower high into the heavens are for the great international passenger liners. From private hangars upon many a roof top fliers were darting into the line of traffic. The north and south traffic has the right of way and the east and west must rise above it. On some towers a incubator of precious metal rests. These may also be found in an inner courtyard. These are the resting places of the Red Men's eggs.
Yet with all the swift movement and the countless thousands rushing hither and thither, the predominant suggestion was that of luxurious ease and soft noiselessnes The sound of music mingles with the whirring of motors and the subdued noises of the city to make a pleasant susseration.
Every roof within both cities was spread with silks and tapestries on which the occupants of the tower would take their leisure. They create splashes of color visible only from the air.
The city is very large. Streets connect all parts of the city. The Avenue of Ancestors down which you could see the full length to the Gate of Jeddaks, five miles away is an example of the scale of this city. The towers are not crowded together, but are seperated by a considerable distace. It is only the length of the great streets that make them look like they strech through tall canyons.

Gate of Jeddaks

The Palace of the Jedak has great steps leading up to the main portals.

The Temple of Reward
It is here that Martian justice is meted to benefactor and malefactor.  to the Temple of Reward up the broad Avenue of Ancestors which eventully leads to the temple plaza . Off of this plaza is the great hall of the temple which is a vast circular coliseum. At one end is the Pedestal of Truth. This is a large stone platform which seats the thirty-one judges of Helium law. Rising above the rear of the Pedestal is the Throne of Righteousness. The highest ranking noble available at the time sits here and oversees the questioning and judges the judges.
The Aisle of Hope leads from the main entrance to the coliseum up to the Pedestal.

The Great Pneumatic Stations of the city.
Approach one that is empty. Upon its nose is a dial and a pointer. Set the pointer for a certain station in Helium, raise the arched lid of the thing, step in and lay down upon the upholstered bottom. There workers walk the craft on its frictionless magnetic tracks through a complicated series of "traces" or track junctions. It is here that the craft are routed to the nearest tubes leading to the chosen destination. Tracks can also be seen on the celing of this area, but the automatic routing machine died when the cities "brain" died when the Gods proscribed electrical conduction.
The instant that its entire length is within the black aperture it sprang forward with the speed of a rifle ball. There
was an instant of whizzing--a soft, though sudden, stop, and slowly the carrier emerged upon another platform,
another attendant raised the lid and Vas Kor stepped out at the station beneath the centre of Greater Helium,
seventy-five miles from the point at which he had embarked.