From Bravo Fleet Infobase
Resurrected from the dusty backwaters of theoretical design history to allow life to go on under immensely challenging planetary conditions, the Lagashi arcology is the single dominant framework of Lagashi civilization - an entire city placed in a single, immense building, with both radii and heights of multiple kilometers and consisting of all the manufacturing, agricultural, business and residential spaces necessary for a society to function. The smallest Lagashi arcologies dwarf any Earth building at 5 kilometers tall, and the largest reach into the Lagashi stratosphere: twenty kilometers above the surface of the planet or more. The Jade Sky arcology, current home of the offices of the Executor and the Federation embassy, presently holds the title of the tallest occupied building in known space at 21,325 meters. One of its nearest competitors, the six other Second Founding arcologies, may well reclaim the title from it in the next few years - expansion of living and business spaces continues to drive these behemoths higher, despite the steep price of living in such prestigious real estate. Only counter-gravity and structural integrity fields allow such massive feats of engineering to remain standing against the pressure of Lagash Prime's hurricane-force winds, even with their bones of super-compressed diamond lattice and an outer skin even stronger than the duranium-alloy battle steel that encased Lagash's early warships. Populations of tens or hundreds of millions bustle through their corridors and grav-lifts, and their crackling urban energy is like nothing dreamed of outside the hearts of Manhattan or Tokyo before the Third World War.
A related form of Lagashi architecture, the astral arcology, is essentially a similar structure built in orbit of a planet. Rather than confining itself to a single tower, an astral arcology is free to spread like kudzu wherever the whims and pressures of its population demand. The largest of these arcologies dwarf starbases, providing cheap and comparatively roomy housing for extremely modest prices - the economic equivalent of an American suburb of the twentieth century. All such arcologies are legally required to mount extensive shielding and transporter systems for emergency evacuation in case of catastrophic accident or attack, but many go beyond this to mount whatever weaponry and exotic defenses their owners and residents are willing to fund or maintain. To look up into the Lagashi sky at night is to see entire constellations of man-made stars as the astral arcologies, orbital power relays and semi-automated farming satellites illuminate themselves for the night.
To explain the experience of visiting a Lagashi arcology, much less living in one, visitors often fall back on metaphors involving white-water rapids or similarly overwhelming and chaotic environments. The endless motion of people, ceaseless commerce and relentless plethora of broadcast material - available for a modest subscription fee, of course - are simply outside the experience of even veteran city-dwellers from other worlds. Yet to a native or a shrewd visitor, this endless storm of activity is an endless opportunity easily navigated to find anything one might need - peace and quiet included.
Most Lagashi begin their mornings with whatever rituals or exercise suit them, often including a quick morning meal shared with those family members whose schedules allow it, followed by the commute to their place of employment. This might be as simple as a walk across the front room to an in-home office, as complex as a ten minute weave through the grav-lift driven public transit system, or as expensive as a personal transporter to deposit her neatly at the reception area for her company. The working day varies in length much as it does in the Federation, though a lunch break is expected during which colleagues may socialize and a return home for a two-hour break which encompasses dinner - usually consisting of unreplicated food that has been hand prepared - and some time with one's family is included in almost everyone's day. Then, a return to work or relaxation and pleasure in whatever fashion that might suit the tastes of the individual Lagashi.
Virtually every form of shopping or entertainment establishment imaginable (and a few you haven't thought of) are available within easy reach within even a modestly-sized arcology, and the largest arcologies include entire multi-level parks dedicated to shopping or recreation. Long-distance transporter links connect most arcologies in any given star system, so that it is almost as easy to find what you need in your cousin or aunt's home arcology as it is in your own and family visits are relatively easy.
Spaces, both public and corporate, vary enormously in size and configuration. The largest on record - Victory Plaza, built in the uppermost spire of the Jade Sky arcology - is a single open 'room' more than two kilometers in radius whose intricate, transparent dome of adamant soars more than four hundred meters above its green grass and dark stone paths, interrupted only by docking ports along its sides for VIP ships. The smallest logged in the official databanks is the two-meter-cubed box which holds the Starslam Club, a notorious little faculty bar which exclusively serves the senior professors of the Academy of Sciences, and a pocket garden with a vivid view of the Broken Coast.
Song of the Stars
Located over T'ien II. One of the first, oldest astral arcologies in the T'ien system, dating from the 2190's.