During the summer solstice, nighttime does not get beyond nautical twilight, a condition which lasts throughout the month of June.
It is possible to view both astronomical dawn and dusk every day of the month of April.
[1] The maximum altitude of the Sun is > 18.00º in October and > 11.00º in November.
The only capital city on the 57th parallel north is Riga.
Starting at the Prime Meridian and heading eastwards, the parallel 57° north passes through: