Natural Pool Oasis.This space is a shining example of how water features and gardens can work well together. A long, narrow, rectangular lap pool is set into the middle of the yard. The shape provides plenty of room for swimming, while the location makes it the centerpiece of the design. Dark ribbons of dwarf mondo grass fill the cracks between flagstones. The mondo grass creates a cooler, less reflective surface and reinforces the natural-looking appearance of the space.