Night Light of Castricum (North Holland) from space (Netherlands) Src. Average luminocity for 10x10km area is 30.5556% and for 50x50km: 23.249%.
Square area 10x10 km:
 3.57%
 3.57% 3.31%
 3.31% 1.85%
 1.85% 6.08%
 6.08% 2.51%
 2.51% 3.04%
 3.04% 2.51%
 2.51% 5.56%
 5.56% 26.19%
 26.19% 30.29%
 30.29% 15.08%
 15.08%Square area 50x50 km:
 6.68%
 6.68% 5.47%
 5.47% 1.8%
 1.8% 1.7%
 1.7% 2.01%
 2.01% 2.08%
 2.08% 2.1%
 2.1% 3.26%
 3.26% 6.69%
 6.69% 11.35%
 11.35% 56.87%
 56.87%Clear (daylight) street map image can be seen on geolist.org.
Map coordinates:
52° 58' 25.7" North, 3° 57' 58.8" East
52° 32' 54" North, 4° 40' 10" East
52° 7' 7.2" North, 5° 22' 21.3" East
Some cities around Castricum sort by population:
• Alkmaar
		10.7 km =6.6 mi,  29°
29°
• Velsen-Zuid
		9.9 km =6.2 mi,  187°
187°
• Beverwijk
		7.3 km =4.5 mi,  186°
186°
• Heemskerk
		4.1 km =2.5 mi,  177°
177°
• Heiloo
		6.2 km =3.9 mi,  11°
11°
• Uitgeest
		3.5 km =2.2 mi,  128°
128°
• Zaandijk
		12.4 km =7.7 mi,  131°
131°
• Limmen
		2.9 km =1.8 mi,  36°
36°
Sources (retrieved 2019-11-25):
» Earth at Night: Flat Maps 2012, 2016