Ostrow Tumski, Poznan

Ostrow Tumski in Poznan has a strong claim to be the cradle of Poland. The first ruler known to history, Mieszko I, is thought to have had his seat here, and it was on this island that Polish Christianity took root after his baptism in 966. The cathedral that stands here is the oldest in the country.

This is where the Polish state and church began, and it is a quiet counterpoint to the busy market square. The island is small and walkable, with the great cathedral at its centre and the river on either side. Come here to understand why Poznan calls itself the place where Poland started, then cross back to the Old Market Square for the livelier centre.

The Archcathedral Basilica of St Peter and St Paul was first built in the year 968 and rebuilt many times since, Gothic above ground and far older beneath. Its Golden Chapel holds the tombs of the first Piast rulers, among them Mieszko I and Boleslaw the Brave. The interior repays a slow look, and the crypt below is part of the visit.

Excavations under and around the cathedral have uncovered the foundations of the earliest churches and of the tenth-century stronghold, some of it displayed where you can stand over the beginnings of the Polish state. The relics of the first cathedral and baptismal structures are the highlight for anyone interested in the origins of the country.

Just across the water, the Brama Poznania heritage centre uses film, sound and models to tell the island's thousand-year story, and it makes a good first stop before the cathedral itself. A footbridge links it to the island.

Mieszko I accepted Christianity in 966, an event that drew the young Polish state into Latin Europe. A bishopric was established at Poznan soon after, and the island became the religious centre of the Piast lands. Later capitals rose elsewhere, but Ostrow Tumski kept its place as a founding site.

Allow about an hour for the cathedral and the excavations, and another hour if you add the Brama Poznania centre across the river.

Mornings and early afternoons are best for daylight in the cathedral and quiet in the lanes. Avoid the main service times on Sundays and church holidays if you want to look around freely. The island is calm in the evening, but most interiors close by late afternoon.

The island is a ten-minute walk or short tram ride east of the Old Market Square, so the founding site and the Renaissance centre fit easily into one day. For the rest of the city, see the Poznan guide.

The main paths and the cathedral's ground floor are broadly step-friendly, but the crypt and excavations involve stairs and uneven surfaces. Brama Poznania across the river is a modern building with full access. Check ahead if step-free routes matter throughout.

The island connects the founding sites with the rest of Poznan:

• The cathedral itself, the centrepiece of the island.
• The Brama Poznania heritage centre, across the footbridge.
• The Old Market Square, about ten minutes west.

It was one of the main seats of Mieszko I, the first historic Polish ruler, and the place where Christianity was established after his baptism in 966. The country's oldest cathedral stands here, over the foundations of its earliest churches.

The Golden Chapel in the cathedral holds the tombs of the first Piast rulers, including Mieszko I and Boleslaw the Brave, under a richly decorated nineteenth-century interior.

It is about a ten-minute walk east, or a short tram ride, so the two sit comfortably in the same day.