Poreč sits on a little limestone peninsula on the western coast of Istria, and the old town still follows the grid the Romans laid down, with the Decumanus running straight down the middle. The Euphrasian Basilica is tucked a few lanes from the main street, behind a quiet atrium, and it is easy to walk past if you are looking for something grand from the outside. Inside is the reason it earned its UNESCO listing: a sixth-century church, built under Bishop Euphrasius, that kept its Byzantine mosaics through a millennium and a half of earthquakes, Venetian rule and tourism.
The apse is the part to stand in front of. Gold tesserae, a Virgin and Child enthroned between angels, the bishop himself holding a model of his church. Under the floor and around the complex there are older layers, the remains of earlier prayer rooms and Roman houses, because Christians here had been meeting in a private house long before anyone built a basilica. The bell tower can be climbed, and from the top you read the whole peninsula, red roofs, marina and the flat blue Adriatic.
For a rider, Poreč itself is a place to arrive on foot. The old centre is mostly closed to traffic, so leave the bike at the edge of town and walk in, and do it early, because by midday the cruise-ship crowd of the coast has found the Decumanus. Fuel is no problem here, with a town of ten thousand people, and there are plenty of cafes along the waterfront promenade where a coffee costs what you would expect for a tourist port.
The better riding starts when you leave. Head inland and the land lifts into the green and red Istrian interior, small roads between vineyards, olive groves and hilltop villages like Motovun and Grožnjan, where the corners are tight but the surface is usually decent and traffic thins out quickly once you are a few kilometres from the coast. Funtana to the south and Tar to the east are the nearest small neighbours, both useful for a quiet back road rather than the busy coastal route. Summer weekends are crowded and hot, so spring and late September are kinder, when the stone is warm and the light slants gold across the apse mosaics and the vineyards alike.