The baptism of Christ
The dome's central scene, with the Jordan personified.
Clodette662000 — CC BY-SA 4.0 · Federico Bragee — CC BY-SA 4.0 · José Luiz — CC BY-SA 4.0 · Stefano Suozzo — CC BY-SA 3.0
**A small octagonal building whose dome is a mosaic of Christ's baptism ringed by the twelve apostles** — beside Ravenna's cathedral, and its oldest building. It was built in the early **5th century** and decorated under Bishop **Neon** (hence the name) around **450**. ⚠ **The octagonal shape is deliberate**: **eight is the number of resurrection** in Christian symbolism — **the eighth day**, beyond the week, the new life. **So almost every baptistery of this period is octagonal.** ✅ **The dome is three concentric rings**: **at the centre the baptism of Christ in the Jordan** — with John, and the river itself personified as an old man; **around it the twelve apostles** circling with crowns; **and beyond them painted architecture**. ✅ **Its floor has sunk three metres** below the modern street.
The dome's central scene, with the Jordan personified.
Twelve apostles circling with crowns.
The lower walls faced in marble and carved stucco.
Piazza Duomo, 48121 Ravenna, Italy
Dante's Tomb**The tomb of Italy's greatest poet in the city Florence exiled him to — and Flo4 minutes walk4.6
Basilica of San Vitale**The greatest surviving Byzantine mosaic outside Istanbul — with Justinian and 7 minutes walk4.9
Sant'Apollinare Nuovo**Two bands of mosaic running the length of the church — a procession of saints 7 minutes walk4.6
Mausoleum of Galla Placidia**A small room whose vault is a night sky of eight hundred gold stars on deep bl8 minutes walk4.7**Because the city was built on marsh and is still subsiding — and the difference runs to several metres.** ✅ **The origin**: Ravenna was built **on wet, alluvial ground** among marshes and a river delta — **which is what made it militarily secure**, and the reason it was chosen as capital. ⚠ **But alluvial soil compresses**: **wet clay and sand consolidate slowly under the weight of buildings** over centuries — **so the buildings sink**. ✅ **Two things compound it**: **groundwater extraction** in modern times sharply accelerated the subsidence, **and relative sea-level rise**. ✅ **The visible result**: **the Neonian Baptistery's floor is some three metres below the street**, **and many of Ravenna's churches are entered by going down** rather than up — **the opposite of the usual**. ⚠ **In some buildings water marks show** on the lower walls. ✅ **The most striking example: the church of San Francesco** — **its crypt is permanently flooded**, **with goldfish swimming above a 10th-century mosaic floor**; **seen through an opening with coin-operated lighting**, ✅ **free, and worth the detour**. ⚠ **The subsidence is a genuine conservation problem** and engineering effort goes into slowing it.