Complex sentence: The Humboldt Botanical Gardens (18 ha/44.5 acres) are located south of Eureka, California, USA near the South Bay portion of Humboldt Bay directly across Tompkins Hill Road from College of the Redwoods.
Split into simpler sentences: The Humboldt Botanical Gardens (18 ha/44.5 acres) are located at the southern edge of Eureka, California, USA. The Gardens are placed near the South Bay portion of Humboldt Bay directly across Tompkins Hill Road from College of the Redwoods.