A visit to the dam brings home the immense technological feat and allows you to gaze out over Lake Nasser, created by the blocking of the river, which is now over 500 km (310 miles) in length, spanning the border with Sudan.
Going to the dam will not provide you with a view of Lake Nasser. 
mnli hypothesis: Going to the dam will not provide you with a view of Lake Nasser.  premise: A visit to the dam brings home the immense technological feat and allows you to gaze out over Lake Nasser, created by the blocking of the river, which is now over 500 km (310 miles) in length, spanning the border with Sudan.