Whenever a road, way, right-of-way, railroad or comparable man-made or man-designed area or feature, or any pond, stream, river, swamp, bog, marsh, or other body of water or comparable natural or quasi-natural geographic features are shown on the Zoning Map as a boundary between districts of different zoning, the geographic district boundary shall be on the center line of such feature. Any such feature lying totally within a designated zone shall be zoned as the other land around it. No part of the land or water area within the Town shall be unzoned.