This astronomical clock was constructed between 1464 qnd 1470 by the clockmaker Hans Düringer of Nuremberg. It’s 14 metres high and was the World’s tallest clock in the 15th century. It was reconstructed after the damages in the Second World War.
The construction of St. Mary began in 1379 and it’s currently the largest brick church in the World because of it’s 105 metres high and the nave is 66 metres wide.
It’s one of the symbols of Gdansk. For example, here you have on German Nazi propaganda poster from 1939 with St. Mary as guest star:
The clock shows the date, the time, the phases and position of the Moon and the position of the Sun in the Zodiac. On the clock Adam and Eve alongside the Three Kings, the Death and the Apostles.
There also are the calendar of the Saints so it’s a very complete clock.
By the way, there is a sundial in one of the lateral facades!
Location: Basilica of St. Mary of the Blessed Virgin Mary in Gdańsk (map)