St Olaf's Church is the largest medieval building in Tallinn, offering stunning views of the historic Old Town from its 60-metre-high viewing platform. First mentioned in 1267, the church was named after the sainted Norwegian king Olav II Haraldsson. The church's prominent spire now stands at 123 metres, but in the 15th century, it reached an astonishing height of 159 metres, making St Olaf's Church one of the tallest structures in medieval Europe.

Fun fact: Lightning is known to have struck the tower of the church at least a dozen times, three of which led to extensive fires – in 1625, 1820, and 1931.