Formerly known as "Kedah Peak", this forest-clad Gunung Jerai is a massive limestone outcrop that rises 1200m above sea level. As the highest peak in the state, it adds a touch of variety to the scenic flat plains seen throughout the area. There are a number of legends and historical facts attached to this mountain. During the Hindu-Buddhist era, it was a sacred mountain. Ruins of Hindu and Buddhist temples were discovered at the foot of the hills. Varied tales of a "Raja Bersiong" (the King with Fangs) also abound. He had once held power over an ancient kingdom near the mountains. Recent archeological findings revealed the existence of the "Temple of the Ninth Water Pool"; many believe that it was Raja Bersiong's private pool. Amidst such majestic surroundings, it is indeed difficult to separate fact from fiction.

Today, its cool fresh mountain air is matched by the quiet serenity of its natural surroundings. On clear days, different vantage points on this mountain offer breathtaking views of Kedah's padi fields, which stretches to Perlis in the north, the emerald seas surrounding Penang in the southwest, and the legendary island of Langkawi in the northwest. The mountain also offers a unique selection of plants, which make it even more intriguing for the botanist. The Sungai Teroi Forest Recreation Park houses an endless variety of herbs, ferns, flowering plants, and climbers. Picnic sites are scattered all over the park, offering sweeping views of lowland plains and padi fields. Hiking trails that are interspersed with flowerbeds of vivid hues provide opportunities for leisurely strolls. Trees along the path are labeled for easy identification. Part of the mountain stream has even been dammed to provide cool clear pools for swimming. For the more adventurous, overnight shelters have also been provided. At the peak of the mountain, the Museum of Forestry houses a wealth of information and artifacts on Malaysian forestry.