Poznan Cathedral — officially the Cathedral Basilica of St Peter and St Paul — stands on Cathedral Island (Ostrów Tumski), the sandy island in the Warta River where Poland's Christian history began. The current Gothic structure is mostly 14th to 15th century, though the crypt below is older and holds remnants of the first Romanesque cathedral from the 10th century. The cathedral was badly damaged in 1945 and rebuilt over the following decade, with the work done sufficiently carefully that the interior retains much of its historic character.
The Golden Chapel, added in the 1840s, contains the tombs of Mieszko I and Boleslaw I in Byzantine-inspired splendour that seems slightly out of keeping with the Gothic nave but is unquestionably impressive. Guided tours are available and worthwhile — the crypt excavations showing the foundations of the original church are genuinely interesting. The island itself, quiet and tree-lined, is a pleasant contrast to the busy city centre a few minutes' walk away.