This magnificent four-arched gatehouse on the waterfront was built as a palace for Polish monarchs. No Polish king ever stayed in the building, but Lech Wałęsa had his office here before moving to the European Solidarity Centre. The gate leads to the Green Bridge, which spans the Motława River and which used to be raised to stop the riff-raff from getting into the Old Town. Following careful renovation, the gate now bears an uncanny resemblance to Amsterdam's central train station, and hosts the Modern Art Gallery and the Gdańsk Photo Gallery. Both often hold exhibitions simultaneously so keep an eye out for reduced-price tickets (One entry for 5zł, Double entry for 6zł).