St. Mark's Basilica - the golden heart of Venice

In a nutshell: a church covered in gold - Byzantine mosaics over 5,000 square yards, the jeweled Pala d'Oro, the original bronze horses - and the official booking link at the bottom. Start from the San Marco overview or the Piazza.

St. Mark's Basilica

St. Mark's lays claim to being the most intriguing church in Europe - a building that, in Goethe's phrasing, 'can only be compared with itself.' The facade is a riotous fusion of East and West: rounded Roman arches above the portals, glowing Byzantine gold mosaics, a roofline crowned with spiky Gothic finials, and Islamic-style onion domes built of timber sheathed in lead. The brick body is wrapped in marble hauled from Constantinople in 1204 - a city that had itself stripped materials from across the eastern Mediterranean: columns from Alexandria, capitals from Sicily, carvings from Anatolia, in purple, green, gray, white and yellow, some mottled, some banded, some fluted. It is little wonder the style earned the nickname 'Early Ransack.' The main doorway is a sixth-century bronze Byzantine panel that may once have swung inside Hagia Sophia in Constantinople, and the church's own plan mirrors the great fourth-century Church of the Holy Apostles in Constantinople, giving the city a venerable (if invented) pedigree. In short, it is a reliquary built atop a saint's purloined remains: the mosaic over the far-left door depicts the heist that put Venice on the pilgrimage route - two merchants leaning on crooked staffs, bearing a coffin that holds the body of St. Mark, who looks thoroughly put out after the lengthy voyage, presented not to any pope or bishop but to the doge (in his white ermine collar) and the dogaressa, an instant prestige boost for the rising secular state. Mark, who wrote one of the four Gospels, met his death as a martyr in Alexandria; in AD 829 a pair of visiting Venetian traders 'liberated' his corpse from Muslim-ruled Egypt - tradition insists they concealed it under a heap of pork, a meat Muslims would not touch - and smuggled it back to Venice. The original church rose over his remains in 832; fire destroyed it in 976, and the structure we see was begun in 1063. A mosaic dated 1260 proves how little the church has evolved since: the onion domes and the celebrated bronze horses on the balcony are all already there. The building is simultaneously a cathedral (the seat of the local bishop), a basilica in the Roman Catholic sense (a title granted to churches of exceptional importance) and a basilica architecturally, its Greek-cross layout of four equal arms echoing the great public halls of ancient Rome that gave the term its name.

Within, the church is radiant: mosaics sheath virtually the entire upper zone - nearly 5,000 square yards, enough to cover a football field - in the Byzantine idiom, although many were designed by Renaissance Italian artists and later figures. The easily missed lower walls are dressed in green, yellow, purple and rose marble slabs sliced to show the grain and arranged in geometric patterns, and the floor itself is mosaic; it undulates like the sea, the settling, shifting city having pushed the stone into slow waves. Begin in the atrium: the 13th-century Noah's Ark mosaic - among the earliest and best - depicts Noah and his sons sawing planks for the Ark (a theme close to Venetian hearts, for the Arsenale shipyard once employed thousands of shipwrights), the creatures boarding in pairs (lions in the lead), the Flood drowning the sinful, the dove dispatched twice, and Noah's thank-offering beneath a spectacular rainbow; a neighboring dome recounts Genesis from solitary Adam in Eden to the fig leaf and expulsion. Inside, the Pentecost mosaic (c. 1125), one of the church's oldest, shows the dove blasting out a pinwheel of holy 'lasers' that kindle tongues of flame over the 12 apostles - with the gold ground, halos, grave faces, almond eyes and crinkled robes that typify Byzantine art, the visual language of a culture still uneasy about 'graven images.' In the central dome, Christ ascends into a star-filled sky riding a rainbow, right hand lifted in blessing over the universe - not the crucified Jesus familiar from most Western churches but a majestic, risen deity; white-robed apostles wave farewell among the olive trees of the Mount of Olives, Mary in blue with golden Greek crosses on her shoulders, while Virtues and Beatitudes gird the dome's base. Seek out Christ as Pantocrator ('Ruler of All'), his halo incised with a cross, blessing with fingers that trace the Greek letters chi and rho, flanked by the initials IC XC for 'IesuC XristoC.' The images are assembled from countless little cubes of stone or glass (tesserae) bedded in fresh plaster - some with gold leaf laminated between glass layers, the surfaces angled unevenly to catch the light - and they narrate the whole of Christian history in reverse: you enter amid scenes of the Apocalypse and Pentecost, then stroll backward through the Passion, the miracles, the Nativity and the Old Testament, with Christ both above the altar and over the entrance as the Alpha and Omega. The building was conceived as a stage: the rood screen, bearing 14 saints on top, divides the congregation from the high altar and deepens the drama of the Mass, and the purple pulpit on the right was the doge's, from which he led prayers and delivered key proclamations; the first modern opera was composed here by the basilica's maestro di cappella, Claudio Monteverdi (1567-1643). In the north transept, worshippers still pray to the Nicopeia (Our Lady of Victory), a painted wooden icon of Mary and the infant Jesus said to have been executed by the evangelist Luke, which carried Venice through plagues, wars and pivotal soccer matches; the crown and jewels that once decked her now reside in the Treasury.

The basilica, closer still

The basilica became Venice's cathedral only in 1807, centuries after it was raised as the doges' private chapel, outshining the official seat of San Pietro di Castello in every way. The facade's oldest mosaic, dated 1270, fills the far-left portal's lunette and shows St Mark's body being carried ashore; while mosaics from 1660 above the portal second in from the right repeat the theme, with turbaned officials stepping away from the pork-fat barrel that hid the corpse. The richest images inside are fused with 24-carat gold leaf applied to the underside of the glass. The narthex keeps the oldest mosaics of all - an Apostles with the Madonna that has guarded the entrance for more than 950 years - next to the atrium's Dome of Genesis, whose abstract take on the parting of water and sky seems to prefigure modern art. The domes read from altar to entrance: the Prophets' cupola hovers over the high altar, the Last Judgment fills the vault over the door (best viewed from the museum), and angels wheel around Christ among the stars beneath the 13th-century Ascension Cupola. The main altar encloses St Mark's plain stone sarcophagus. Set into the south wall near the Porta della Carta is the Four Tetrarchs, a porphyry statue group of about 300 CE showing Diocletian - ironically a ferocious enemy of the Christians - with the three co-rulers of his short-lived Tetrarchy, hauled away from Constantinople amid the Fourth Crusade.

Behind the high altar, the Pala d'Oro (€5) glitters with roughly 2,000 precious stones - rubies, sapphires, amethysts, emeralds and pearls - but its true treasures are the biblical figures in vivid cloisonné enamel, started in Constantinople in 976 and reworked by local goldsmiths in 1209; spot the falcon-hunting vignettes in the lower medallions and, on the right, the familiar episode of the corpse carried off from Egypt. The Treasury mingles crusader booty with holy relics - a rock-crystal ewer from the 10th century, winged of foot, crafted for the Fatimid ruler al-'Aziz-bi-llah, a bejewelled 12th-century icon of the Archangel Michael whose tiny enamelled saints look ready to leap out of their gilded frame; off to one side rest the femur of St Roch, the arm that St George used against the dragon - plus, improbably, a strand of the Madonna's hair. From the museum's upper floor, the Loggia dei Cavalli terrace delivers a bird's-eye prospect over the piazza, and Salviati's restored family-tree mosaic lines an interior balcony, its branches crowded with Mary's ancestors, some chatting, others ignoring one another. The most bewitching way in, though, is an after-hours visit, which spends about 90 minutes in the emptied basilica, with generous time before the Pala d'Oro and a descent into the normally off-limits crypt beneath the church, where St Mark's bones rest; book it days ahead on the official site. Worshippers enter free through the Porta dei Fiori; evening vespers admit visitors after hours, though only as far as the Madonna della Nicopeia chapel.

The 99-metre Campanile was first raised in 888 and has risen anew twice since, most recently in 1912 after the dramatic collapse of 1902. Galileo Galilei tried out his telescope from up here in 1609, and attentive ears can pick out the Marangona, the great bronze bell that once marked the start and finish of the artisans' working day. Children under seven ride free; lines are long in peak season, so book a skip-the-line slot online well ahead, or take the lift up the similarly dramatic tower at San Giorgio Maggiore instead.