The pond and bog garden provide a place to relax and contemplate the natural world. Recovered from a construction site and dug by volunteers, the pond demonstrates the value of a water feature in a garden and encourages wildlife activity. Water flowing over a rocky outcrop creates a woodland oasis in an urban setting, while the waterfall and biological filter remove excess nitrogen through beneficial bacteria and clarify the water, creating a healthy habitat for aquatic plants, fish, and amphibians. The bog garden and walkway reflect the character of bogs in nature and the plants adapted to low-fertility, waterlogged landscapes. A bog garden has permanently moist soil and provides habitat for plants and creatures that thrive in such conditions. It may use naturally poor drainage or be artificially created with pond liners or other materials that trap water, as here. Typically, bog-garden soil is acidic and low in nutrients, and plants that thrive in it include pitcher plants, ferns, sedges, and wild ginger.