diff --git a/core-java-modules/core-java-collections-array-list-2/src/main/java/com/baeldung/peakelements/MultiplePeakFinder.java b/core-java-modules/core-java-collections-array-list-2/src/main/java/com/baeldung/peakelements/MultiplePeakFinder.java
new file mode 100644
index 0000000000..f8e13ee86e
--- /dev/null
+++ b/core-java-modules/core-java-collections-array-list-2/src/main/java/com/baeldung/peakelements/MultiplePeakFinder.java
@@ -0,0 +1,40 @@
+package com.baeldung.peakelements;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class MultiplePeakFinder {
+
+    public static List<Integer> findPeaks(int[] arr) {
+
+        List<Integer> peaks = new ArrayList<>();
+
+        if (arr == null || arr.length == 0) {
+            return peaks;
+        }
+        findPeakElements(arr, 0, arr.length - 1, peaks, arr.length);
+        return peaks;
+    }
+
+    private static void findPeakElements(int[] arr, int low, int high, List<Integer> peaks, int length) {
+
+        if (low > high) {
+            return;
+        }
+
+        int mid = low + (high - low) / 2;
+
+        boolean isPeak = (mid == 0 || arr[mid] > arr[mid - 1]) && (mid == length - 1 || arr[mid] > arr[mid + 1]);
+        boolean isFirstInSequence = mid > 0 && arr[mid] == arr[mid - 1] && arr[mid] > arr[mid + 1];
+
+        if (isPeak || isFirstInSequence) {
+
+            if (!peaks.contains(arr[mid])) {
+                peaks.add(arr[mid]);
+            }
+        }
+
+        findPeakElements(arr, low, mid - 1, peaks, length);
+        findPeakElements(arr, mid + 1, high, peaks, length);
+    }
+}
diff --git a/core-java-modules/core-java-collections-array-list-2/src/main/java/com/baeldung/peakelements/PeakElementFinder.java b/core-java-modules/core-java-collections-array-list-2/src/main/java/com/baeldung/peakelements/PeakElementFinder.java
new file mode 100644
index 0000000000..857ae3b1b2
--- /dev/null
+++ b/core-java-modules/core-java-collections-array-list-2/src/main/java/com/baeldung/peakelements/PeakElementFinder.java
@@ -0,0 +1,44 @@
+package com.baeldung.peakelements;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class PeakElementFinder {
+    public List<Integer> findPeakElements(int[] arr) {
+        int n = arr.length;
+        List<Integer> peaks = new ArrayList<>();
+
+        if (n == 0) {
+            return peaks;
+        }
+
+        for (int i = 0; i < n; i++) {
+            if (isPeak(arr, i, n)) {
+                peaks.add(arr[i]);
+            }
+
+            while (i < n - 1 && arr[i] == arr[i + 1]) {
+                i++;
+            }
+        }
+
+        return peaks;
+    }
+
+    private boolean isPeak(int[] arr, int index, int n) {
+        if (index == 0) {
+            return n > 1 ? arr[index] >= arr[index + 1] : true;
+        } else if (index == n - 1) {
+            return arr[index] >= arr[index - 1];
+        } else if (arr[index] == arr[index + 1] && arr[index] > arr[index - 1]) {
+            int i = index;
+
+            while (i < n - 1 && arr[i] == arr[i + 1]) {
+                i++;
+            }
+            return i == n - 1 || arr[i] > arr[i + 1];
+        } else {
+            return arr[index] >= arr[index - 1] && arr[index] >= arr[index + 1];
+        }
+    }
+}
diff --git a/core-java-modules/core-java-collections-array-list-2/src/main/java/com/baeldung/peakelements/SinglePeakFinder.java b/core-java-modules/core-java-collections-array-list-2/src/main/java/com/baeldung/peakelements/SinglePeakFinder.java
new file mode 100644
index 0000000000..f7b7cfc72b
--- /dev/null
+++ b/core-java-modules/core-java-collections-array-list-2/src/main/java/com/baeldung/peakelements/SinglePeakFinder.java
@@ -0,0 +1,30 @@
+package com.baeldung.peakelements;
+
+import java.util.OptionalInt;
+
+public class SinglePeakFinder {
+    public static OptionalInt findSinglePeak(int[] arr) {
+        int n = arr.length;
+
+        if (n < 2) {
+            return n == 0 ? OptionalInt.empty() : OptionalInt.of(arr[0]);
+        }
+
+        if (arr[0] >= arr[1]) {
+            return OptionalInt.of(arr[0]);
+        }
+
+        for (int i = 1; i < n - 1; i++) {
+            if (arr[i] >= arr[i - 1] && arr[i] >= arr[i + 1]) {
+                return OptionalInt.of(arr[i]);
+            }
+        }
+
+        if (arr[n - 1] >= arr[n - 2]) {
+            return OptionalInt.of(arr[n - 1]);
+        }
+
+        return OptionalInt.empty();
+    }
+}
+
diff --git a/core-java-modules/core-java-collections-array-list-2/src/test/java/com/baeldung/peakelements/MultiplePeakFinderUnitTest.java b/core-java-modules/core-java-collections-array-list-2/src/test/java/com/baeldung/peakelements/MultiplePeakFinderUnitTest.java
new file mode 100644
index 0000000000..bc145c654d
--- /dev/null
+++ b/core-java-modules/core-java-collections-array-list-2/src/test/java/com/baeldung/peakelements/MultiplePeakFinderUnitTest.java
@@ -0,0 +1,23 @@
+package com.baeldung.peakelements;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class MultiplePeakFinderUnitTest {
+
+    @Test
+    void findPeaks_givenArrayOfIntegers_whenValidInput_thenReturnsCorrectPeaks() {
+        MultiplePeakFinder finder = new MultiplePeakFinder();
+        int[] array = {1, 13, 7, 0, 4, 1, 4, 45, 50};
+        List<Integer> peaks = finder.findPeaks(array);
+
+        assertEquals(3, peaks.size());
+        assertTrue(peaks.contains(4));
+        assertTrue(peaks.contains(13));
+        assertTrue(peaks.contains(50));
+    }
+}
+
diff --git a/core-java-modules/core-java-collections-array-list-2/src/test/java/com/baeldung/peakelements/PeakElementFinderUnitTest.java b/core-java-modules/core-java-collections-array-list-2/src/test/java/com/baeldung/peakelements/PeakElementFinderUnitTest.java
new file mode 100644
index 0000000000..fc521272b4
--- /dev/null
+++ b/core-java-modules/core-java-collections-array-list-2/src/test/java/com/baeldung/peakelements/PeakElementFinderUnitTest.java
@@ -0,0 +1,46 @@
+package com.baeldung.peakelements;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class PeakElementFinderUnitTest {
+
+    @Test
+    void findPeakElement_givenArrayOfIntegers_whenValidInput_thenReturnsCorrectPeak() {
+        PeakElementFinder finder = new PeakElementFinder();
+        int[] array = {1, 2, 3, 2, 1};
+        List<Integer> peaks = finder.findPeakElements(array);
+        assertEquals(1, peaks.size());
+        assertTrue(peaks.contains(3));
+    }
+
+    @Test
+    void findPeakElement_givenArrayOfIntegers_whenNoPeaks_thenReturnsEmptyList() {
+        PeakElementFinder finder = new PeakElementFinder();
+        int[] array = {};
+        List<Integer> peaks = finder.findPeakElements(array);
+        assertEquals(0, peaks.size());
+    }
+
+    @Test
+    void findPeakElement_givenArrayOfIntegers_whenPeaksAtExtremes_thenReturnsCorrectPeak() {
+        PeakElementFinder finder = new PeakElementFinder();
+        int[] array = {5, 2, 1, 3, 4};
+        List<Integer> peaks = finder.findPeakElements(array);
+        assertEquals(2, peaks.size());
+        assertTrue(peaks.contains(5));
+        assertTrue(peaks.contains(4));
+    }
+
+    @Test
+    void findPeakElement_givenArrayOfIntegers_whenPlateaus_thenReturnsCorrectPeak() {
+        PeakElementFinder finder = new PeakElementFinder();
+        int[] array = {1, 2, 2, 2, 3, 4, 5};
+        List<Integer> peaks = finder.findPeakElements(array);
+        assertEquals(1, peaks.size());
+        assertTrue(peaks.contains(5));
+    }
+}
diff --git a/core-java-modules/core-java-collections-array-list-2/src/test/java/com/baeldung/peakelements/SinglePeakFinderUnitTest.java b/core-java-modules/core-java-collections-array-list-2/src/test/java/com/baeldung/peakelements/SinglePeakFinderUnitTest.java
new file mode 100644
index 0000000000..9e4cea2c0e
--- /dev/null
+++ b/core-java-modules/core-java-collections-array-list-2/src/test/java/com/baeldung/peakelements/SinglePeakFinderUnitTest.java
@@ -0,0 +1,32 @@
+package com.baeldung.peakelements;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import java.util.OptionalInt;
+
+public class SinglePeakFinderUnitTest {
+
+    @Test
+    void findSinglePeak_givenArrayOfIntegers_whenValidInput_thenReturnsCorrectPeak() {
+        int[] arr = {0, 10, 2, 4, 5, 1};
+        OptionalInt peak = SinglePeakFinder.findSinglePeak(arr);
+        assertTrue(peak.isPresent());
+        assertEquals(10, peak.getAsInt());
+    }
+
+    @Test
+    void findSinglePeak_givenEmptyArray_thenReturnsEmptyOptional() {
+        int[] arr = {};
+        OptionalInt peak = SinglePeakFinder.findSinglePeak(arr);
+        assertTrue(peak.isEmpty());
+    }
+
+    @Test
+    void findSinglePeak_givenEqualElementArray_thenReturnsCorrectPeak() {
+        int[] arr = {-2, -2, -2, -2, -2};
+        OptionalInt peak = SinglePeakFinder.findSinglePeak(arr);
+        assertTrue(peak.isPresent());
+        assertEquals(-2, peak.getAsInt());
+    }
+}