Gjennomsnittlig GPS-koordinater for postnummer 20981: 3.268, 98.8
Notering byer:
>> Silinda 20981, North Sumatra, Serdang Bedagai, GPS-koordinater: 3.26799,98.79969
Notering byer:
>> Silinda 20981, North Sumatra, Serdang Bedagai, GPS-koordinater: 3.26799,98.79969