The Longest Construction Projects in History: Why Sagrada Família, the Milan Duomo, Greek Temples & Other Famous Structures Took Generations to Complete

Pub­lic-tran­sit projects are the reli­gious build­ing endeav­ors of twen­ty-first cen­tu­ry Amer­i­ca, less because they’re moti­vat­ed by the belief in any par­tic­u­lar deity than by how much time and mon­ey they now require to com­plete. Take New York’s Sec­ond Avenue sub­way, whose less than two-mile-long first phase opened in 2017: its con­struc­tion had cost $4.45 bil­lion, and the line itself had first been pro­posed 97 years ear­li­er. That’s noth­ing by ancient stan­dards: the Tem­ple of Apol­lo at Didy­ma took six cen­turies; the Tem­ple of Olympian Zeus at Athens lagged a full 650 years behind sched­ule; and the Heraion of Samos end­ed up pass­ing the 800-year mark.

These facts come from the new Told in Stone video above on “the longest con­struc­tion project in his­to­ry.” Some of the struc­tures cov­ered will be famil­iar to Open Cul­ture read­ers: for instance, Notre-Dame de Paris, which took near­ly 200 years to build (and which reopened just this month after five years of fire-dam­age repair and restora­tion), or Sagra­da Família, which broke ground in 1882 and is sched­uled for com­ple­tion in 2026 — if you don’t count dec­o­rat­ing its exte­ri­or, which could go on until 2034. Orna­men­ta­tion is impor­tant in archi­tec­ture of this kind: it’s why the Duo­mo di Milano, whose con­struc­tion began in 1386, was­n’t tru­ly com­plete until 1965.

The dec­o­ra­tion process was also pro­longed in the case of the Basil­i­ca Papale di San Pietro in Cit­tà di Vat­i­cano, or Saint Peter’s Basil­i­ca, which took 120 years to build, span­ning the ear­ly six­teenth and sev­en­teenth cen­turies. As the time­line goes for such an ambi­tious project in that era, it could have been worse; that par­tic­u­lar High Renais­sance church owes its noto­ri­ety to its sheer cost, which works out to “tens of bil­lions” of dol­lars today. This video, being Microsoft-spon­sored, leads up to that soft­ware giant’s 3D, AI-assist­ed repli­ca of Saint Peter’s Basil­i­ca, which we fea­tured here on Open Cul­ture when it was released this past fall. Per­haps behold­ing its glo­ry will give New York­ers a lit­tle more faith that the Sec­ond Avenue Sub­way will reach 125th Street in their life­times.

Relat­ed con­tent:

An Archi­tec­tur­al Tour of Sagra­da Família, Antoni Gaudí’s Auda­cious Church That’s Been Under Con­struc­tion for 142 Years

The Cre­ation & Restora­tion of Notre-Dame Cathe­dral, Ani­mat­ed

Explore the World’s First 3D Repli­ca of St. Peter’s Basil­i­ca, Made with AI

The Beau­ty & Inge­nu­ity of the Pan­theon, Ancient Rome’s Best-Pre­served Mon­u­ment: An Intro­duc­tion

How the World’s Biggest Dome Was Built: The Sto­ry of Fil­ip­po Brunelleschi and the Duo­mo in Flo­rence

How Design­ing Build­ings Upside-Down Rev­o­lu­tion­ized Archi­tec­ture, Mak­ing Pos­si­ble St. Paul’s Cathe­dral, Sagra­da Família & More

Based in Seoul, Col­in Marshall writes and broad­casts on cities, lan­guage, and cul­ture. His projects include the Sub­stack newslet­ter Books on Cities and the book The State­less City: a Walk through 21st-Cen­tu­ry Los Ange­les. Fol­low him on the social net­work for­mer­ly known as Twit­ter at @colinmarshall.