Zone district boundary lines as shown on the Zoning Map[1] accompanying this chapter are intended to coincide with lot lines, the center lines of streets, drainage courses or railroads as they existed at the time of adoption of this chapter, or they are designated on the Zoning Map by figures or dimensions. Whenever a zoning district boundary is located not farther than 25 feet away from a lot line of record, such boundary line shall be construed to coincide with such line. In case of uncertainty or disagreement as to the true location of any zone boundary line, the determination thereof shall lie with the Board of Adjustment.