The Basilica of the National Shrine of the Immaculate Conception is the largest Catholic church in the United States and North America, one of the ten largest churches in the world, and the tallest habitable building in Washington, D.C. Construction of this church, notable for its Neo-Byzantine architecture, began in 1920 under Philadelphia contractor John McShain. It opened unfinished in 1959. An estimated one million pilgrims visit the basilica each year.
The basilica is designated both as the national and patronal Catholic Church of the United States, honoring the Virgin Mary, under the title Immaculate Conception, by which Pope Pius XI donated a mosaic of the same image in 1923.
The basilica houses 70 chapels honoring Mary and reflecting the origins of the Catholic immigrants and religious orders whose generosity erected them. Its Greek-styled interior is crowned with numerous domes decorated in mosaics, similar to the Basilica of St. Mark in Venice, Italy, but much larger. The mosaics feature American renditions of traditional Catholic images. Artist Jan Henryk De Rosen, who presided over the shrine's iconography committee was also responsible for much of its decor, including composing the large mosaic over the northern apse.
The exterior of the basilica is 152m long, 73m wide, and 72 m tall to the top of the cross on the dome. The shrine was built in the style of medieval churches, relying on masonry walls and columns in place of structural steel and reinforced concrete. It was designed to hold 10,000 worshipers.
In all, 70 chapels and sacred images flank the sides of the upper church and crypt. It contains many works of art. There are arches outlined with iridescent Pewabic Pottery tile, large ceramic medallions set in the ceiling, and fourteen Stations of the Cross for the crypt.
References:The ancient Argos Theater was built in 320 BC. and is located in Argos, Greece against Larissa Hill. Nearby from this site is Agora, Roman Odeon, and the Baths of Argos. The theater is one of the largest architectural developments in Greece and was renovated in ca 120 AD.
The Hellenistic theater at Argos is cut into the hillside of the Larisa, with 90 steps up a steep incline, forming a narrow rectilinear cavea. Among the largest theaters in Greece, it held about 20,000 spectators and is divided by two landings into three horizontal sections. Staircases further divide the cavea into four cunei, corresponding to the tribes of Argos A high wall was erected to prevent unauthorized access into the theatron and may have helped the acoustics, but it is said the sound quality is still very good today.
Around 120 CE, both theaters were renovated in the Roman style.