diff --git a/Terrain2Tests/AlgorithmsTests.swift b/Terrain2Tests/AlgorithmsTests.swift
index 17858b1..9a1475f 100644
--- a/Terrain2Tests/AlgorithmsTests.swift
+++ b/Terrain2Tests/AlgorithmsTests.swift
@@ -13,7 +13,25 @@ public typealias Box = DiamondSquareAlgorithm.Box
 public typealias Point = DiamondSquareAlgorithm.Box.Point
 public typealias Size = DiamondSquareAlgorithm.Box.Size
 
-class DiamondSquareBFSTests: XCTestCase {
+class DiamondSquareBoxTests: XCTestCase {
+
+    func testMidpoint() {
+        let box = Box(origin: (x: 3, y: 4), size: (w: 5, h: 5))
+        let midpoint = box.midpoint
+        XCTAssertEqual(midpoint.x, 6)
+        XCTAssertEqual(midpoint.y, 7)
+    }
+
+    func testSubdivision() {
+        let box = Box(origin: (x: 3, y: 4), size: (w: 5, h: 5))
+        let subdivs = box.subdivisions
+        XCTAssertEqual(subdivs.count, 4)
+        XCTAssertEqual(subdivs[0], Box(origin: (x: 3, y: 4), size: (w: 3, h: 3)))
+        XCTAssertEqual(subdivs[1], Box(origin: (x: 6, y: 4), size: (w: 3, h: 3)))
+        XCTAssertEqual(subdivs[2], Box(origin: (x: 3, y: 7), size: (w: 3, h: 3)))
+        XCTAssertEqual(subdivs[3], Box(origin: (x: 6, y: 7), size: (w: 3, h: 3)))
+    }
+
     func testBFS() {
         let box = Box(origin: (x: 3, y: 4), size: (w: 5, h: 5))
         var expectedBoxes: [Box] = [
@@ -42,7 +60,7 @@ class DiamondSquareBFSTests: XCTestCase {
             Box(origin: (x: 8, y: 7), size: (w: 2, h: 2)),
             Box(origin: (x: 6, y: 9), size: (w: 2, h: 2)),
             Box(origin: (x: 8, y: 9), size: (w: 2, h: 2)),
-        ].reversed()
+            ].reversed()
 
         box.breadthFirstSearch { (box: Box) -> (Void) in
             let exBox = expectedBoxes.popLast()
@@ -51,9 +69,39 @@ class DiamondSquareBFSTests: XCTestCase {
         }
         XCTAssertEqual(expectedBoxes.count, 0)
     }
-}
 
-class DiamondSquareBoxTests: XCTestCase {
+    // MARK: Sides
+
+    func testNorth() {
+        let box = Box(origin: (x: 3, y: 4), size: (w: 5, h: 5))
+        let pt = box.north
+        XCTAssertEqual(pt.x, 6)
+        XCTAssertEqual(pt.y, 4)
+    }
+
+    func testWest() {
+        let box = Box(origin: (x: 3, y: 4), size: (w: 5, h: 5))
+        let pt = box.west
+        XCTAssertEqual(pt.x, 3)
+        XCTAssertEqual(pt.y, 7)
+    }
+
+    func testSouth() {
+        let box = Box(origin: (x: 3, y: 4), size: (w: 5, h: 5))
+        let pt = box.south
+        XCTAssertEqual(pt.x, 6)
+        XCTAssertEqual(pt.y, 9)
+    }
+
+    func testEast() {
+        let box = Box(origin: (x: 3, y: 4), size: (w: 5, h: 5))
+        let pt = box.east
+        XCTAssertEqual(pt.x, 8)
+        XCTAssertEqual(pt.y, 7)
+    }
+
+    // MARK: Corners
+
     func testNorthwest() {
         let box = Box(origin: (x: 3, y: 4), size: (w: 5, h: 5))
         let pt = box.northwest
@@ -81,21 +129,4 @@ class DiamondSquareBoxTests: XCTestCase {
         XCTAssertEqual(pt.x, 8)
         XCTAssertEqual(pt.y, 9)
     }
-
-    func testMidpoint() {
-        let box = Box(origin: (x: 3, y: 4), size: (w: 5, h: 5))
-        let midpoint = box.midpoint
-        XCTAssertEqual(midpoint.x, 6)
-        XCTAssertEqual(midpoint.y, 7)
-    }
-
-    func testSubdivision() {
-        let box = Box(origin: (x: 3, y: 4), size: (w: 5, h: 5))
-        let subdivs = box.subdivisions
-        XCTAssertEqual(subdivs.count, 4)
-        XCTAssertEqual(subdivs[0], Box(origin: (x: 3, y: 4), size: (w: 3, h: 3)))
-        XCTAssertEqual(subdivs[1], Box(origin: (x: 6, y: 4), size: (w: 3, h: 3)))
-        XCTAssertEqual(subdivs[2], Box(origin: (x: 3, y: 7), size: (w: 3, h: 3)))
-        XCTAssertEqual(subdivs[3], Box(origin: (x: 6, y: 7), size: (w: 3, h: 3)))
-    }
 }