Shimba Hills National Reserve Day Safari from Mombasa Island is a Day Trip to Shimba Hills National Reserve located 56 kilometers from Mombasa. The park is 74 Square Miles in size and access to the Park is via Diani South Coast. The most distinctive of the Shimba Hills National Reserve’s many species is perhaps the rare and impressive Sable Antelope, found in the same habitats as several large herds of buffalo.